is this normal? brown period and weird discharge?

i had protected sex twice about a month ago and a few weeks ago i got a weird white discharge (usually my discharge is a slightly creamy colour) then i got my period which was heavy and red for the first two days and then was a brown colour the last three days. i got the weird discharge again about a week after my period ended. is this normal? any ideas or just my body and hormones changing (i’m 15) ? pregnant?