i agree with ashelen you must call your doctor and tell about your conditon or go to ER.
alright I don't know if you're trying to do a home birth or whatnot, but I have to say that any time pain brings you to tears, ESPECIALLY in pregnancy, it's your responsibility to go to the ER or at least call your doctor. You must take care of yourself, and pain is the body's indication that something is not right...please call your doctor/midwife and/or go to the ER...good luck sweetie.
could be spd, i had it, look it up on internet and consult midwife