7 to 8 days after my period, i have dark brown discharge especially after sex. day 2 after my period had unprotected sex with ejaculation. mean what?

Intermenstrual Bleed: Spotting/ brownish discharge in between cycles is called intermenstrual bleeeding. It can be normal, or related to a small uterine infection. Some birth control meds can also cause it. Sex 2 days after a normal cycle would be very unlikely to result in a pregnancy. If you are at risk for pregnancy, consider a home preg test. I recommend you mark your periods on a calender to track them.