If there is only a little red bleeding at the time of menstruation and then it clears up, this is highly suspected to be caused by pregnancy, so it is better to draw blood for blood HCG because blood HCG is more sensitive and urine HCG may be missed, so it is better to draw blood for blood HCG to find out if you are pregnant. When the blood HCG is >10mIU/mL, it indicates pregnancy and further tests are recommended to rule out intrauterine pregnancy, ectopic pregnancy, or biochemical pregnancy. Therefore, in case of menstruation, it is necessary to give the appropriate diagnosis before the next step can be taken. If the laboratory tests do not indicate pregnancy, it is possible that some disease may be the cause. Ultrasound and sex hormone tests are recommended and treatment will be given according to the results.