Painful Sex

Okay - is there anyone else out there with this problem? Most of the time when I'm trying to "do the do" with my husband sex is quite painful. It's like a stabbing pain (quick & fast) it doesn't last it's just really sudden. I have Noticed right before my period it goes away and I can get down like I used to before I started having this problems. (Why is that so?) I mainly have the problem when it's straight on contact or just spread eagle situation. LOL All joking aside though it really hurts and it also discourages me & my husband. I have had (3) surgeries for cysts & endometriosis removal and still have this problem. I just find it really crazy that right before my period comes the pain goes away! Just wondering anyone has any insight on this and why it might be?