Hi Pixie, sorry about your m/c. I had a MMC last November. My AFs were messed up for several months. Like you, the first was heavier and longer. Then I had one much earlier than expected, then the next one was over a week late. Now they seem to have settled down.
I think it really depends, and doctors pretty much say anything goes as long as you do get a period after (is it?) 8 weeks, I think. I had bleeding exactly 28 days after ERPC for mmc, but it was not like a period, heavy at first, no cramps, then all but disappeared. Then got what really did feel like a proper period 29 days after that, but a bit heavier and a bit longer. Spoke to my gynae (who suggested I take agnus castus and vit E) and she said it all sounds pretty normal, but things are usually expected to be pretty all over the place for a few months.
I have to say, though, emotionally, it was nice to have a "proper" period (though sad too...)