When i am having sex my boyfriend nuts in me all the time, but this time when he first sticks his penis in its painful and i feel it start to cramp in my lower stomach...what could this be?also sometimes my stomach starts to hurt during intercourse?

Pelvic pain with sex: Make sure you're properly lubricated before penetration. Adequate foreplay and/or use of KY jelly would help. You may have a tilted uterus and deep penetration and forceful thrusting can provoke pelvic pain. Try having intercourse lying on your side. An examination by a gynecologist could determine whether a tilted uterus is present.