Help!

i usually start my period at the end of every month. the 27th, 28th. so this month i got off my period on the 3rd, the day after me and my boyfriend had unprotected sex. on the 16th, two weeks after we had sex and two weeks before i’m due to start my next period i started bleeding a light brown red, now on the 25th im still bleeding slightly off and on the same color.. any help i don’t know what this is ...