A little bit of blood in the lower part of the body when you are 40 days pregnant, and then there is no, may be caused by the first sign of miscarriage, ectopic pregnancy or cervical polyps and other reasons. 1. Pre-eclampsia: can cause irregular vaginal bleeding in early pregnancy, also accompanied by paroxysmal abdominal pain, ultrasound suggests intrauterine pregnancy, combined with progesterone and blood hCG (human chorionic gonadotropin) test can assist in the diagnosis, you need to comply with the doctor’s instructions to give birth control treatment. 2. Ectopic pregnancy: also cause early pregnancy irregular vaginal bleeding, and accompanied by one side of the lower abdomen pain, combined with ultrasonography, blood hCG can help diagnosis. After the diagnosis is clear, we should follow the doctor’s instructions to actively treat. 3. Cervical polyp: it can cause repeated irregular vaginal bleeding, which can be diagnosed by gynecological examination and ultrasonography. It is necessary to follow the doctor’s advice to perform surgical removal, and sent to the pathology examination. If you are pregnant and have a little bit of blood under 40 days and then no symptoms, you need to go to the hospital in time to find out the cause, and under the guidance of the doctor to actively treat.