Hello,
Thank you for your question. Normal menstrual cycles vary considerably during the first few years after
menarche, the majority of cycles in adolescents last 21 to 45 days with two to seven days of menstrual bleeding. The average adult menstrual cycle lasts 28 days to 35 days with four to six days of menstrual bleeding. The median blood loss during each menstrual period is 30 ml, the upper limit of normal is 80 ml.
If you use birth control pill make sure that you take it regular everyday.
stress and tired also can effect your menstrual period. Right now you can wait from 21 to 45 days if still not period you can do
Pregnancy test. If your pregnancy test is negative, you should wait and see. Until if your menstrual period still absent for more than 3 months, you should go to see your doctor. Your doctor may do some test related to your general condition Some kind of disorder can cause you absent period. They may check
TSH the measurement of
thyroid stimulating hormone, screening for STIs if indicated by sexual/reproductive history and other cause depend on your history and examination condition.
Hope I have answered your query. Let me know if I can assist you further.
Best regards,
Dr. Heang Chan Raksmey, General and Family Physician.