Opinions please! TMI!

Last night my s/o and I had sex. This morning I used the bathroom and there was alot of brown discharge with is obviously old blood. I called my doctors and they said my cervix was probably just irritated. Im still having the discharge thought. Im currently 8 weeks and 2 days pregnant. Has this happened to anyone else, how long did it take to stop? this is my first pregnancy so im just freaking out! Any input would be appreciated, thank you!