Pain On Left Ovary

I have been having pain on my left side for about 7 months now. I went to my gyno and he found a cyst, 2 months later I went back for another test and it was gone. I still have pain on my left side. Its mostly a dull constant pain but gets worse around my period. I also had extreme pain one night after intercourse and I thought I was going to die. It was the worse pain I have ever felt in my life. My doctor just tells me its pelvic pain and that a lot of women compain of it. He wont do anything for me and im worried that something could really be wrong. Help me :cry: