Level 1: Causes of Bleeding in the First Month of Pregnancy Bleeding in the first month of pregnancy may be caused by a variety of reasons. The most common of these is early miscarriage, which occurs when the embryo dies naturally and is expelled from the body before 6 weeks of pregnancy. Other causes include cervical disease, infection, or ectopic pregnancy. If you suspect you may be experiencing an early miscarriage, seek medical advice promptly. Level 2: Symptoms of early miscarriage Typical symptoms of early miscarriage are vaginal bleeding and abdominal pain.