I'm so sorry for your loss sweetie..
I had an early loss but I did have messed up cycles after that. Mine were painless and very light and short (I also only had one every 2 or 3 months) for about a year after then they straightened themselves out. That is very unusual though. I had some problem that my Dr was never able to lay a finger on. My periods did straighten themselves out and before I got pregnant with my little girl, I had like 8 normal periods. It's very common for cycles to be screwy after a loss either early or late, but if after like 3 or 4 cycles, my OB told me to come in if they were still abnormal. Like I said, don't let my case scare you, as mine was very unusual.