Lower abdominal pain, vaginal pain?

today, my boyfriend and I began to have sex. it was just casual soft sex. nothing crazy... well we was only doing it for maybe 6min whenever i started hurting. it started like on the inside on my vagina.. and it went on like the top part of my vagina and down to my butthole. and the lower part of my stomach. well it hurt really bad. i curled up into a fetus position and laid there for like 20min and wouldnt move because it hurt so bad. I'm supposed to start my period in 4 days. does my period have something to do with it? ell the top part of my vagina still hurts a lil bit. like when i walk or cough. i dont know. ive never felt anything like this before. and i dont know what it could be caused from.