What Causes Delay In Menstruation Other Than Pregnancy?

I am a 17 year old girl and I haven't had my period yet. I was supposed to have it on the 23 and it is the 2nd of June. I am sexualy active, but we use condoms. But anyways, I am feeling pain down there, and it feels like I have to pee and then i go pee and it strings and blood comes out. The string like shoots down my legs in my feet. It hurts so bad. Right after I pee I feel like i have to again but only a little comes out and blood. What is wrong with me?