Question-irregular periods after MC

Shelby

I had a MC on April 24th of this year. It's was a pretty early miscarriage. Anyways, I had my first period May 28-31, didn't have one in June, had one July 1-3 & the 26-August 2, & then another one August 16-19. I was supposed to start again on Sunday (the 17th). My breast are really sore & at first is was only one so I assumed my period was going to come on time this month & things were going to go back to normal. However, it hasn't come yet & now both my breast are pretty sore. I've taken 2 pregnancy test, both negative. I have a doctors appointment scheduled already, but I was just curious if this has ever happened to anyone else?