No Menstruation with Endo?

Have had lower right stabbing pain right before my period for many years.  The pain is also brought on with exercise such as if I do situps.  I have always been irregular.  (Had first menstruation at 16, now 21 yrs. old).

Just recently I had a simple cyst rupture which left me with horrible bloating and more severe symptoms.  I was put on Loestrin24Fe and have yet to have a period in 3 months since the cyst.  Everytime I am "supposed" to get my period the sharp pelvic pain is really intense, and I will have urinary frequency, pain with full bladder, and sometimes the feeling of cramps. The pain is also intensified when laying down or on my side.

Gyn doctor blew me off since sonograms show no cyst and sent me to a GI doctor since she thinks the bloating is not Gyn related.  So now I'm going for a bunch of GI scans next week which I doubt will show a thing since I have no other GI symptoms but bloating.

I've been reading a lot of your posts and was just curious if people with endometriosis have these sort of symptoms I described.  Does endo cause irregular or absent cycles?  Interested to hear if anyone has had or is dealing with a similar experience..... Thanks!