my gf has bad pain when we have sex

hello i am 19 and my girlfriend is 17 we have been together for just over four years now when i first met her she was a virgin and so was i we used to have sex all the time and it was fine dint hurt her and then not so long ago she had bad pains when we tried to have sex so she went to the doctors and got checked over that all come back fine so the doctor referred her to the gynecologist she went up there to have an examination she told me it was real painful for her she was crying and they did some test they all came back fine they said she might need surgery am petrified and she is too they said they wont be able to see her till April.  we still try have sex but it is painful for her she swells up round the entrance to her vagina if any one got any help or advice would be much appreciated thanks :(