Help?

So about three weeks ago, I began birth control. I started taking it on the last day of my period as the doctor suggested and then began taking it nightly. On the sixth day of taking it, I had unprotected sex with my boyfriend. A little over a week ago I started to get weird brown discharge daily, I began to worry but then supposed it could just be my body adjusting to the medication. I got my period today just like normal, but I also couldn’t help but worry about pregnancy? I believe you’re supposed to take seven days of the pill before becoming sexually active, and i can’t help but worry the brown discharge could somehow be linked to pregnancy?