Sorry I'm late to this thread Shay.
As Kate mentioned, I have pretty severe Endo. I've been on every form of BC you can imagine (7 pills, patch, ring, etc). And have had 2 surgeries.
TMI, but I used to have trouble with spotting and cramping after intercourse. I still do occasionally. At one point I was on Vicodin and bedrest for cramps.
From what you mentioned in your post, I would guess it is time to change the BC, if that is a treatment that works for you. The hard part of having Endo is that every woman is different and you can't tell how bad it is without looking inside. The amount of pain you experience has nothing to do with the amount or location of the lesions.
I would advise making an appointment ASAP with a doctor and getting an ultrasound.
As far as fertility issues, with proper treatment, you can go on to conceive and deliver a perfectly healthy baby. Ironically, having a child will usually "cure" you.
I was mis-diagnosed for years, and that is why I've had the number of problems I did.
Feel free to PM or E-mail me with any questions. I'm really open about the matter. When I was first diagnosed at 19 I had no one to turn to and really didn't understand the severity of my condition. I'm happy to help in any way that I can.
Good luck!