If you are pregnant, you will not have your period in the first month.
The main manifestation of pregnancy is menopause, menstruation is caused by the sudden drop in hormone levels after ovulation, the corpus luteum will continue to secrete estrogen and progesterone after pregnancy, and since there is no drop in hormones, it will not cause the uterine lining to shed and bleed, which means it will not cause menstruation.
If you have vaginal bleeding after pregnancy, you should consider the situation of preeclampsia, biochemical pregnancy, etc. You should go to the hospital in time for examination and receive birth control treatment. In the early stage of pregnancy, as the embryo is still unstable, you should keep resting as much as possible, avoid strenuous exercise, and have regular checkups to observe the development of the embryo.