Helppppp

I am 19 and I am not on birth control. Usually my periods are pretty regular. I ended my period about a week ago then it came back a whole day later. Once it completely went away I started bleeding again during sexual inter course. After that I was “bleeding” a brown really watery substance that is very strong in smell and that has been happening for 2 days now. Not having any pain but any idea what’s going on??!