I had sex with my boyfriend, and a day after around my belly button was hurting and little below it? we used a condom and he didn't ejaculate?

Belly button pain: This may be related to the coital activity. Too early for pregnancy. If the pain is recurrent, a proper evaluation by a gynecologist is indicated.

Cramping: The uterus extends into the abdomen and has multiple ligamentous connections with the walls of the belly. It is possible that you are having cramping as a result of your prior activities. This would be similar to a workout routine that causes achy muscles a day or two later.