While on my period, i had anal sex, he did not ejaculate inside of me. after my period i had a brown discharge for 2 days and now i'm having cramps?

Unclear question : It is unclear exactly what you were asking or wanting to know. If the brown discharge was from your vagina and that's likely leftover blood from your menstrual cycle. If the brown discharge was from your anus then it may just be excremental leaking. You ought to be checked for lacerations, tears, and infection if it continues.