TTC with irregular cycle

I'm going to be 31 this year and me and my husband are TTC I currently have a 9 and 7 year old from my previous relationship. I had two Nexplanon's and had it removed last june 2017 and have only had one cylce since then, I am on my second round of Medroxyprogesterone from my doctor but he said this is the last dose I can have and to see if my body goes back to normal after. I am afraid it won't. is there anyone else who has experienced this and may have some advice?