Nausea/Vomiting. Nausea is quite common in the first trimester and may or may not be accompanied by vomiting. This is known as morning sickness, though it can be experienced later in the day as well. The severity can differ from person to person. It isn’t totally clear what the cause is for morning sickness, but it may be due to hormonal changes.

Tender/Swollen Breasts. In the APA survey cited above, about 17% of women surveyed reported this as the first sign of pregnancy. However, this can occur between four and six weeks into pregnancy. You may experience tingling, aching, and swelling/enlargement of the breast tissue. You may also notice darkening of the areas surrounding the nipples. Once your body adjusts to your new hormonal changes, these feelings should subside.

Light Spotting/Bleeding/Vaginal Discharge. This is known as implantation bleeding and occurs after the fertilized egg attaches to the uterine wall. Implantation bleeding could be mistaken for a menstrual period, but there are some distinct differences. Some of the key differences include a smaller amount, shorter time, lighter color, and absence of clotting.

Cramping and pain. The cramps women experience when pregnant may seem similar to those during PMS. But just as we mentioned above with implantation bleeding, implantation cramps are different. These cramps would be present even after you’ve missed your period. Other pregnancy signs and symptoms include leg cramping and soreness in the lower back.

Headaches are so common that this one can’t be relied upon alone. In this case, you may also be experiencing lightheadedness or dizziness. These symptoms would be due to hormonal changes in your body. You should consider them in conjunction with other pregnancy symptoms you’re experiencing.

Sensitivity to Smell. Though there may be little scientific consensus on this one, it remains a commonly reported symptom. Sensitivity to smell is something that many women report particularly in the early stages of pregnancy. It may also be one of the causes of nausea during this time.

Change of Appetite. Does the Caesar salad you normally love seem a little off-putting? Or does your craving for potato chips and spicy salsa seem out of character? Change of appetite is common as an early sign of pregnancy. Often, the foods you normally desire won’t sound good to you at all. This may also be due to hormonal changes and along with changes in your senses.

Frequent Urination. Having to hop up and run to the bathroom in the middle of the night? Unless you’re hydrating like crazy, that could also be one of the pregnancy signs and symptoms to watch for. Also due to hormonal changes, it’s possible to experience this even before missing your period.

Constipation and Bloating. Speaking of hydration, that’s not a bad idea considering this symptom can be very uncomfortable! If you’ve had fewer than three bowel movements in a given week, you may be dealing with pregnancy constipation. Hormonal changes can be the culprit behind bloating and constipation.

Mood Swings/Fatigue. Mood swings and fatigue are also attributable to hormonal changes. This is because your body is producing a hormone called progesterone. This hormone supports the pregnancy and is responsible for milk production in the breasts as well. As soon as one week after conception, you could experience fatigue due to your body working harder to pump additional blood to support this new life.

Heartburn, or indigestion may affect more women in the second and third trimesters. However, it’s generally considered to stem from your increase in progesterone levels, so don’t rule it out. Especially if it’s not something you normally experience.