Hi.
I had sex 12 hours ago with condom.
I hadn't had sex for a long time so it was kinda painful and had strange pains in my stomach.
After 12 hours i got a gush of dark brown, slimy discharge that was odorlous though had some clots.

I finished my period a week ago though it wasnt a normal period and didnt last as long as usual.

Can someone please offer me advice with what this could be?
Or some reasons why this happened?

Thanks
Z