The normal menstrual cycle is between 21 and 35 days, the average being 28 days. If you have bleeding 21 days early, you are not pregnant, but have irregular menstruation, and you should check the HCG of your blood to see if you are pregnant. It is meaningless to do ultrasound during this period. If you have taken emergency contraceptives, it can also cause early menstruation and vaginal bleeding. Normal women without fertility requirements must do a good job of contraception, insist on every sexual life with a condom, or take short-acting contraceptives Eusebio or Eusebio, abortion due to unplanned pregnancy is very harmful to the body, so be sure to protect yourself.