Brown Discharge and foul smell after late period!!!!

I am 18 years old and have been sexually active for about 1 year now. I have been safe and only had sex with one person who had sex with only one person before me. We use a condom each time we have sex. We are engaged and don't get to see eachother a lot due to the fact that he lives a few hours away going to a different college. When I do see him we have sex a lot something like 6 - 12 times in one weekend. Last month my period was 15 days late. Just recently I have been having these horrid abdomnal pains sometimes when we have sex and sometimes when I am not having sex. Now my vagina lets out this Brown dirty yellow discharge that smells sour and very foul. I don't know what it could be and it worries me. Somebody please help!!! WHAT COULD IT BE???

If you started having pain during sex, it could be that you have endometriosis. It is a condition in which the cells that make the uterine lining grow on other organs besides the uterus like on ovaries, bladder, Fallopian tubes or bowells. Uterine lining develops after ovulation and it is preparing for the fertilised egg to implant in there. When fertilization (egg meets spermatozoid) doesn't occur, this lining breaks down and this is what we shed as a period. The same thing happens with lining that develop on other organs, it wants to go out but it has no place to go. THis condition often causes pain during intercourse, periods as well as cramping, so you should see a gynecologist and tell all about your symptoms.

Bleeding/Spotting could occur due to infections as well but you said you had used condoms every time, right?