###Human: My last period lasted only for few hours with a history of unprotected sex. Should I worry? ###Assistant: Hello. I can understand your concern. According to your statement, you have been suffering from tenderness in your breast and little bit fatigue. Your last menstrual period was on 15th April which lasted for 15 hours and you had unprotected sexual intercourse on 4th. Usually, woman's menstrual cycle is 28 days (+/-7days) normally. So if period occurs seven days before the estimated date as well as seven days after the estimated date is quite normal. It may happen in every woman in her lifetime. It is nothing to be worried. Again menstrual bleeding can last for 2-7 days normally. So your last menstrual bleeding lasted for 15 hours which may be quite normal. You should not worry about that. You should know about the safe period during a normal menstrual cycle. It is also known as calendar method. In this period no woman becomes pregnant from unprotected sex. If your menstrual cycle is 28 days, then from the 9th day of your last menstrual cycle to the 16 th day of your last day of menstruation will be counted as danger period (from 9th day to 16th day, total 7 days are known as danger period). In this period a woman can bear pregnancy from unprotected sexual intercourse. The rest 21 days are counted as safe period. In this period no woman can become pregnant from unprotected sex. So, luckily 4th April was your safe day. So there is no chance for you to become pregnant. Hormonal fluctuations can cause breast tenderness. Breasts may become painful before three to five days of starting of a menstrual period and stop hurting after your period begins. Menstrual cycle causes hormone fluctuations in estrogen and progesterone which make your breasts swell and can lead to sore and discharge. Those hormonal imbalance may make you fatigue too. I hope this helps.