Wondering if you might be pregnant? The best way to be sure is by taking a pregnancy test. However, a woman can look for certain early pregnancy symptoms. These include missing periods (the first sign of pregnancy), morning sickness, having sore breasts, mood swings, frequent urination, bloating, constipation, fatigue, body changes, etc. The earliest signs of pregnancy are caused due to the rise in the level of pregnancy hormone(hCG) and female sex hormone. Visit the Outlook Health website for more information about pregnancy signs and symptoms.