1. Delayed or shortened menstruation One of the signs of the first month of pregnancy is delayed or shortened menstruation. If your cycle is usually regular but is unusual this month, it could be that you\’re pregnant. When the fertilized egg enters, it implants inside and begins to grow. This process may cause light bleeding or brown discharge, called implantation bleeding. If this happens during your expected period, you may be pregnant. 2. Breast swelling, pain and sensitivity. Signs of the first month of pregnancy also include breast