###Human: How to detect pregnancy after having an unprotected sex? ###Assistant: Hi. She has got periods twice after having unprotected intercourse. Her first period can be due to the withdrawal effect of drugs, and the second episode after a month can be a regular period. Change in breast size can occur during regular menstrual periods. But it is usually not noticeable. You have not mentioned whether there was an ejaculation done or not. So if you think that there is a change in size, I would advise you to do a urine pregnancy test for your partner. As it is more than eight weeks, it will detect pregnancy if it is there.