I need help gals

Okay this is going to be quite long but I need help🙃😂

I had unprotected sex but he didn't finish in me so I'm pretty sure I'm not pregnant ( I wasn't sure if this would be relevant or not) I started taking the pill the period after this and I've started getting a brownish discharge, I usually get this for 2 days after my period but it's lasted over a week! Could this be due to the pill or is there something more serious??