How early do pregnancy symptoms start?
If you have been trying your best to get pregnant, it is natural to know if you are pregnant at the earliest, even before you miss your periods or start experiencing nausea and vomiting.[1,2] Before you miss a period and take a pregnancy test, many signs of pregnancy before missed period can become apparent as early as just two to three weeks of becoming pregnant.  In fact, there is an astonishing number of very early signs of pregnancy before missed periods that can confirm a positive pregnancy result. [4,5,6]
Early pregnancy symptoms before missed period
Here are the common early pregnancy symptoms before missed periods that become obvious even before you miss your first period.
1. Sensitive, Sore, and Heavy Breasts
Tenderness or soreness in your breasts is often one of the very early pregnancy symptoms in many women. Changes to the breasts can begin as early as one to two weeks after conception takes place. While sore breasts can be a pain, but for those who have been actively trying to get pregnant, then this could be the earliest sign of pregnancy you have been waiting for. 
Pregnancy hormones are responsible for making the breasts sore and swollen, or they may also feel fuller or heavier to touch. Experiencing sore nipples and painful breasts are usually the first symptom of pregnancy. Many women start feeling these breast-related changes even as early as just seven days after conception. 
According to the US Department of Health and Human Services, breast pain can occur as early as one to two weeks after conception, which technically indicates weeks three and four of your pregnancy. You will feel the painful breast sensation at its peak during the first trimester as your body gets flooded with pregnancy hormones.
These hormones are getting your body ready to grow your baby inside, and since your breasts are the primary source of food for the tiny human, these hormones work overtime to prepare your breasts for breastfeeding. Due to this, blood flow to that area increases, and your breasts grow larger. However, this growth is usually painful and can even cause skin itching and irritation.
2. Veiny Breasts
Another of the earliest pregnancy signs related to your breasts is the appearance of ‘veiny boobs.’ Veins are present throughout our bodies, and their primary function is to enable blood to be transported to the heart.  While you cannot see them under your skin, but they are always there.
Sometimes, veins become more visible through the skin in the breasts. This development is especially a noticeable condition during early pregnancy. A better way of describing this is that the veins that were already present in your breasts suddenly become more visible when pregnant.
This phenomenon happens because there is an increase in your blood volume by nearly 20 to 40 percent when you become pregnant. [11, 12] When you are pregnant, your veins are responsible for transporting nutrients, blood, and oxygen to the developing fetus. Due to the increased volume of blood, the veins become more visible under your skin. The veins become less visible once you give birth, but it can continue to be present afterward, especially if you are breastfeeding.
3. Changes in your Nipples
You may notice changes in your nipples as well. Your nipples tend to change significantly during the first few weeks of pregnancy. They may start to hurt, tingle, or may even protrude more than usual. Many women also notice that the areoles, which is the dark circle around your nipple, become larger and darker. . A lot of women often notice tenderness in the nipples as the first sign of pregnancy, typically after one or one and a half weeks before their periods were due.
4. Missed or Late Periods
According to the American Pregnancy Association, missing your monthly period or being late is one of the most well-known signs of pregnancy. One in three women finds that a late or missed period is their first pregnancy symptom. 
While there are many other symptoms that you may notice, but this is usually the big sign that prompts most women to take a pregnancy test. However, it is essential to note that a missed or delayed period is not a confirmed sign of being pregnant. Sometimes hormonal problems, weight changes, and recently stopping your contraception might also impact the timing of your periods, causing it to be delayed or missing a month altogether.
For many women, delayed and irregular periods are quite normal, so it is useful to know about the other early pregnancy symptoms before missed periods. 
5. Spotting or Light Bleeding
Many women experience light spotting or bleeding during the early weeks of pregnancy. It can occur in nearly 20 percent of all pregnancies and is typically associated with implantation bleeding.  Implantation bleeding happens when the embryo or the fertilized egg attaches itself to your uterus’s wall. The period when the embryo generally implants is between 6 to 12 days after conception.
However, not all women experience spotting, so there’s no need to worry if you don’t get it. This action is in no way a reflection of whether the implantation has been successful.
It is essential to understand that while in most cases, spotting is nothing to worry about, but sometimes it can be a sign of a more serious condition such as an ectopic pregnancy or a miscarriage. So if you experience any bleeding or spotting that is unusual for you, you should consult your doctor at the earliest. [17, 18]
6. Feeling queasy
One of the most well-known symptoms of pregnancy is morning sickness. However, while it is usually said that morning sickness can begin after 10 to 15 days of conception, some women may start to feel queasy as early as a week into your pregnancy due to several hormonal changes. 
Many women report feeling travel sick when they are in the car or on the bus. Of course, not every woman who is pregnant feels suck and throws up. However, it is estimated that around nine in ten women will suffer from nausea or vomiting, which tends to continue until 12 weeks or the first trimester. 
For women who are having a bad bout of morning sickness, it is recommended that they eat little meals spaced out throughout the day. Also, ensure that you increase your fluid intake. In extreme cases, your doctor will prescribe anti-nausea medication.
7. Period-like Pain
Many women report experiencing this confusing symptom, especially just around the time when they would generally be expecting their periods to start. If you have been trying to get pregnant and begin feeling period-like cramps, and there is no sign of your periods, this could be an early sign of pregnancy. However, this is considered to be one of the less common symptoms of early pregnancy. For some women, this symptom can also be accompanied by spotting as a result of the embryo implanting into the uterus wall.
One of the lesser symptoms of pregnancy is bloating. Bloating is usually due to the rising levels of progesterone. Progesterone is responsible for bloating as it allows the smooth muscles of the bowel walls to relax. . Many women experience bad bloating during the first trimester, but not everyone experiences this early pregnancy symptom.
9. Stomach Cramps
Stomach cramps can also be accompanied with spotting and are usually caused as the ligaments start to stretch out as the uterus begins to change shape. . Many women report feeling sharp stomach pains within a week after ovulation. They also reported feeling tired and cramps at the time of their periods, and after a week, they started feeling nauseous.
10. Tummy Twinges
This phrase might be a new term for many. However, those who experience this early pregnancy symptom are well aware of what tummy twinges mean. These are the curious feeling of pinching and pulling in the stomach that many women experience in early pregnancy. Tummy twinges feel like the muscles being pinched or stretched from the inside. You can also feel tummy twinges on either side of the stomach. Many women report feeling lower abdominal twinges, often on one side, but some also experience them on both sides. They occur due to the stretching and changing of everything inside to accommodate the developing fetus.
Constipation is a common side effect of the increase in the levels of progesterone in the body. This hormone relaxes the bowel walls, making it harder to have a bowel movement. . The solution to treating constipation while pregnant is more or less the same as when you are not pregnant. This includes increasing the intake of fiber, fruits, and vegetables, and increasing your water intake. 
12. Urinate more often
If you are pregnant, you will suddenly find yourself needing to use the washroom more often over the next couple of months. A Taiwanese study discovered that frequent urination affects over 75 percent of all pregnant women. . At the starting stages of your pregnancy, it is not the weight of the growing fetus on the bladder that causes increased urination. Instead, it increases blood flow to the kidneys by nearly 40 to 60 percent, causing more urine to be collected in the bladder.
13. Urinary Tract Infections (UTIs)
As surprising as it may sound, increased trips to the washroom could signify a potential urinary tract infection. UTIs are also more likely when you are pregnant, especially from week 6 to week 24. Reduced levels of immunity during pregnancy, even if it is still in the early stages, is usually responsible for increased susceptibility to various infections such as UTIs. . UTIs are also more common in pregnancy because of the changes in your urinary tract. As the uterus grows, the increased weight can lead to a blockage of urine from the bladder. The blockage occurs as the uterus sits directly on top of your bladder. This process eventually causes an infection.
Some of the common symptoms of a UTI during pregnancy include:
● Sharp stinging sensation while passing urine
● Sharp pain in the lower abdomen
● Need to urinate more often than usual
● Sense of urgency while urinating
● Mucus or blood in the urine
● Pain during sexual intercourse
● Change in the amount of urine – it can either be more or less
● Urine that appears to be cloudy and smells foul
If the bacteria causing the infection spreads to your kidneys, you may also experience chills, fever, back pain, nausea, and vomiting. It is never wise to ignore any indications that you might be having a UTI, especially if you are pregnant. You should immediately consult your doctor.
It might indeed sound like pregnancy humor, but diarrhea and constipation can both be a part of your early pregnancy stages. It might even be that if you are not constipated, you are experiencing diarrhea. Many expectant mothers have shared this symptom as being something they noticed during the first few weeks.
15. Changes in Cervical Mucus
Many women have reported that they seem to have more cervical mucus than usual in their pregnancy. In the early days of pregnancy, the cervical mucus appears to be quite thin and slippery for a longer period than usual (remember that the mucus’ texture keeps on changing throughout your normal monthly menstrual cycle), and it starts to thicken as the levels of progesterone increases. This thickening of the mucus is one of the sure-shot early signs of pregnancy before missed periods. 
Another common symptom in pregnancy is thrush (a white coating or patches on the tongue or mouth), which is again believed to be due to the increased level of progesterone. A study published in the American Journal of Obstetrics and Gynecology found that women are twice as likely to develop thrush during pregnancy as at any other stage in their life. . There are many symptoms of thrush, including soreness, itchiness, and painful urination. 
17. Other Signs of Early Pregnancy
While there are many other early pregnancy symptoms, here are some others that you may experience:
– Excessive tiredness
– Vivid dreams
– Feeling dizzy
Is diarrhea a symptom of early pregnancy?
Some women consider diarrhea an early indication of pregnancy. It’s a fact that hormone changes around the time of conception can lead to stomach difficulties and even result in diarrhea. But, breast tenderness, fatigue, and nausea are a lot more common symptoms of early pregnancy.
Many of these signs and symptoms can easily be confused with the signs of your periods or premenstrual symptoms (PMS). Some of the signs, such as nausea, vomiting, breast tenderness, mood swings, and frequent urination, are more common pregnancy signs than others. Keeping an eye out for these symptoms can help you understand you are pregnant even before you miss your periods.