Some people seem to know they're pregnant soon after conception takes place. Others have no symptoms for weeks, other than a missed period. The only way they know they’re pregnant is by taking a home pregnancy test or a blood test at the doctor’s office.
The bottom line: Early pregnancy symptoms vary widely from person to person.
Here’s what happens in early pregnancy — and some of the most common early pregnancy symptoms to watch for.
What Happens in the First Few Weeks of Pregnancy?
Technically, you’re not even pregnant for the first two weeks of pregnancy, so you won’t have any symptoms. This is because doctors count the first day of your last menstrual period as the beginning of pregnancy. As your pregnancy — which lasts 40 weeks — moves forward, they call this your baby’s “gestational age.”
About 14 days after the first day of your last period, one of your ovaries releases an egg. The egg travels down one of the fallopian tubes, where it unites with sperm. If a sperm fertilizes the egg, it creates an embryo.
The embryo moves down the fallopian tube and toward the uterus. If it implants in the uterine wall, pregnancy occurs. The embryo’s cells keep dividing as it grows.
This embryo carries the chromosomes, or DNA, of both egg and sperm. They're the building blocks of your baby’s genetic makeup.
How Soon Can I Tell I’m Pregnant?
Some people start to have symptoms soon after conception, but others don’t notice symptoms until later in the pregnancy. Early signs of pregnancy can feel like premenstrual syndrome (PMS) symptoms, so you may not immediately realize you’re pregnant.
Even if you experience early symptoms, like spotting, cramps, and fatigue, the only sure way to tell you’re pregnant is through a pregnancy test. Pregnancy tests detect human chorionic gonadotropin (HCG), which your body starts producing more of soon after conception.
For the most accurate results, you should take a home pregnancy urine test after you miss a period. Some tests claim results as early as 10 days after conception, but they might give you a false negative reading. If you get a negative test and then miss a period, you should take another pregnancy test.
Your doctor can also do a blood test for pregnancy in the office.
Symptoms of Early Pregnancy
You may notice symptoms of early pregnancy as soon as one week after conception.
They include:
- Breast changes — Because your hormone levels change quickly after conception, your breasts may become swollen, tender, or sore. They may feel heavier or fuller, and the areola (the area around your nipples) may become darker. These changes usually start happening one or two weeks after conception takes place.
- Fatigue — You might start feeling unusually tired. Pregnancy causes high levels of progesterone, a female sex hormone that can make you feel sleepy and relaxed. Other reasons for fatigue include lower blood sugar, lower blood pressure, and a boost in blood production to nourish your growing baby.
- Missed period — This is the most obvious early pregnancy symptom and the one that prompts most people to take a pregnancy test. However, you can miss a period for reasons other than pregnancy, such as starting perimenopause, being under stress, being underweight or overweight, changing birth control methods, or having thyroid problems or diseases like polycystic ovary syndrome (PCOS).
- Nausea — Morning sickness is a classic early pregnancy symptom. Doctors aren’t sure exactly what causes morning sickness, which isn’t just limited to the morning. Some women experience nausea throughout their pregnancies, but for most, it subsides in the second trimester.
- Spotting and cramping — A few days after conception, the fertilized egg attaches to the wall of your uterus, causing light bleeding. It may feel like the cramps you get when your period is about to begin, or the spotting and cramping may be barely noticeable.
- Vaginal discharge — Almost immediately after conception, the walls of your vagina start to thicken. This produces a white, milky discharge that may continue throughout your pregnancy. (This discharge is normal and harmless, but if it starts to have a foul smell, burns, or itches, contact your doctor immediately.)
What Should I Do if I Think I’m Pregnant?
If you think you’re pregnant but haven’t yet taken a pregnancy test, it’s safest to proceed as though you are pregnant. Until you take a pregnancy test at home or in the doctor’s office, you won’t know for sure. You don’t want to do anything that could harm you or your developing baby.
You should take the following precautions if you think you may be pregnant:
Cut down on caffeine — A cup of coffee or tea (or two) is fine. But too much caffeine can interfere with a healthy pregnancy.
- Eat a healthy diet — To sustain a healthy pregnancy, you should fuel your body with enough calcium, protein, and iron. Aim for balanced nutrition, with lots of fruits, vegetables, whole grains, dairy, and healthy fat sources, like nuts and avocados.
- Get regular, moderate exercise — Being fit can ease pregnancy symptoms and help your body prepare for the hard work of labor and delivery.
- Give up alcohol and/or recreational drugs — They can harm both you and your unborn baby. No amount of alcohol is safe to drink during pregnancy.
- If you smoke, make every effort to quit — Chemicals in cigarette smoke, such as nicotine and carbon monoxide, can harm an unborn baby. Secondhand smoke is also harmful, so if your partner smokes, encourage them to quit.
- Stay away from toxic substances — Frequent exposure to chemical solvents, pollutants, or lawn and farm pesticides may harm a growing fetus. Take steps to minimize your exposure by wearing protective masks, gloves, glasses, and clothing around potentially toxic materials.
- Strive for a healthy body weight — Being too heavy or too thin puts you at risk for premature birth and other pregnancy complications.
- Take a prenatal vitamin — Doctors recommend taking prenatal vitamins (or a multivitamin with 400 micrograms of folic acid) when you’re pregnant, especially early on. Folic acid helps prevent defects in a baby’s spine and brain three to four weeks after conception.
Finally, you should make a doctor’s appointment as soon as you have a positive home pregnancy test. Good prenatal care is essential for a healthy pregnancy and delivery.
Last reviewed by a UPMC medical professional on 2024-09-05.
