l pain durring . soreness.?

hi. durring no matter how long we spend warming up, no matter how slow i take it with either a fingure or "the real deal" after mabe 1 to 2 minutes, my girlfriend complains of a soreness thats like a sore bone or somthing in side the . its a little scary because this never happened before and we were on a pritty regular schedual. how ever its been this way for nearly 2-2 1/2 months. cant go anywhere. oral is ok. no pain there but just penitration. any ideas as to what the ailment might be?