While some women may not know they are pregnant for a month or more, many women notice symptoms of pregnancy right away. The earliest signs of pregnancy may be overlooked, especially if you have an irregular menstrual cycle, as they can be confused with symptoms of an impending period. However, pregnancy symptoms may begin almost immediately, as little as ten to 14 days after fertilization.
Basal Body Temperature
Basal body temperature can be one of the first indicators of pregnancy. Basal body temperature is your body's core temperature when you wake in the morning (before you get out of bed or move around: after this, your temperature goes up). Women often use basal body temperature to track their fertile days, though it can also flag a pregnancy. Just before your period, your temperature, which is higher after ovulation, drops back to baseline. If it stays elevated for 14 days or more, you are most likely pregnant.
Nausea
A few weeks after you become pregnant, you may feel nauseous or notice a heightened sense of smell. According to the Mayo Clinic, this often happens because estrogen levels rise quickly during early pregnancy, and can affect the way food moves through the stomach. Certain smells may also trigger nausea. Don't be fooled by the term "morning sickness," however: Nausea can strike at any time, day or night.
Cramps and Spotting
About two weeks after an egg is fertilized, it implants somewhere on the uterine wall. When this happens, you may experience some light bleeding, also known as spotting. You may also have period-like cramps. While this is one of the earliest signs of pregnancy, it can go unnoticed, and may be mistaken for the start of a period.
Fatigue
Another very early symptom of pregnancy is extreme fatigue. During the first few weeks of pregnancy, you may begin to feel exhausted for no reason at all, though there is a good reason for it. According to the Mayo Clinic, rising progesterone levels associated with pregnancy can cause extreme fatigue. Additionally, your body begins making extra blood almost immediately after conception to support your growing baby. This can lower blood pressure and blood sugar, both of which may leave you feeling exhausted.
Swollen Breasts
The breasts may begin to swell and may become tender to the touch early on in pregnancy. Nipples may feel extra sensitive or tingly and the breasts themselves may feel larger and heavier. They may even look a bit different.
