Bled after sex

I just came off my period a day ago and today me and my husband just literally had sex. We haven’t had sex in well almost a month. Last time we had sex was in Middle of September. Today I bled a little. Wasn’t like crazy heavy bleeding it was just mix with discharged. Is it bc he hit to hard and it irritated me/ cervix or could it been a little too rough idk! We both are clear for std and everything.