STD? Infection? Someone please help!!

So long story short I am 16 and I'm talking to a 21 yr old. I know, not okay and all that but it sorta just happened. He isn't pressing for sex like most do, in fact he says he wants to wait. But we do get physical, bj and fingering, etc. so 5 days ago was one of those times. Yesterday I noticed my discharge has a brown color to it which I know is not normal... I have a strict Christian family and I'm never allowed to leave the house so I can't go to a clinic. Someone please help!!! What do I do??