Ok I'm scared idk what's going on with my body. I ended my period about 12 days ago. Two days after that I had sex. (Not my first time) Afterwards I was a little sore down there. Lasted for a few hours. Then about 3 days later I noticed some light spotting. No pain. No other symptoms just a dark brown color / dark red. This lasted for about 7 days and now the spotting seems like it's getting heavier. Like it's real blood coming out and it doesn't look like spotting to me. What could this be? Could I be pregnant? Infection? Stress? Or what!? Please help im a 17 year old girl who has never had irregular periods before...