According to Medline Plus, spotting in early pregnancy can be due to hormone changes, the implantation of the egg in the uterus, an infection, ectopic pregnancy or a miscarriage. Although spotting and bleeding are not always dangerous early in pregnancy, a woman should call her physician if it occurs.
Early signs of pregnancy are often confused with PMS symptoms, according to Parenting.com. They include tender, swollen breasts, cramping, fatigue, headaches and mood swings. Unlike PMS, shortness of breath and dizziness are common symptoms of early pregnancy. Even if experiencing early pregnancy symptoms, home pregnancy tests are most effective after a missed period. Blood tests are more accurate early in pregnancy.