I had unprotected sex two weeks ago but there was no ejaculation for I was scared. A weel ago I had sex but the condom slipped off so I decided to take a contraception pill. A week later(yesterday) I went for a run and when I came home I had light brown(not pink or red)discharge. Then the next day it was red brown discharge? The spotting lasted for just 2 days.

Was it implantational bleeding? An infection? or was it caused by the running? I am seventeen years old.