can someone ease my mind?

Im 25 and have been TTC since May of 2017. I got pregnant in August of 2017 and miscarried September 24.. my doctor and I weren't positive i could get pregnant because I have endometriosis... once I had my miscarriage my doctor told me this was positive because we now know I can get pregnant... fast forward to present day.. I have stopped having periods... I had one in November and December and haven't had one since. My doctor put me on Provera and it didn't work.. I'm now having to go on another medicine for 3 weeks to try and get a period.. my concern is that I'm not going to be able to get pregnant.. I got pregnant once so I think that's a good sign.. I guess I just need some peace of mind..