Bloody help!

So I've always had a very normal cycle. I had a miscarriage in April and I didn't regain my normal cycle until 6 weeks after. Well for the past few months, my cycle has been coming on 21, 26, or even 24 days after the last one. Have anyone else experienced that. I've scheduled to see my ob next month. I read somewhere that a cycle every 21-35 days is normal. Mines have always been 28-30 days apart. I'm not on bc, no medications, my periods aren't heavy, no cramps... just a little advice if you will!