PAIN AFTER SEX

Q: I had sex with my boyfriend two days ago. right after he pulled out of me i felt a tremendous amount of pain in my abdomen and it felt as though i was constipated as well. today (two days later) i woke up and went to the bathroom. i went to the bathroom probably several times and the first 3-4 times i saw blood when i wiped from urinating. the bleeding only came when i urinated and stopped later that day. then my stomach on the left side began to hurt similarly to the way it hurt the night we had sex. but this time it felt as if i had major gas and at times it felt like cramps and the pain went from the front of my stomach on the left side to my back. then it began to hurt a little on my right side later today. what is it? am i pregnant? do i have a urinary infection? gas? or what?