Weird spotting/period

So I got the copper IUD, have a 10 month old who is still breastfed, and I've had 2 pp periods so far. This time, I'm having a lot of brown spotting and what I thought was the beginning of my period, but it went away and then spotting came back a day later. The past two periods, I've had a couple days of spotting and then a really heavy period, but so far no actual blood. Anyone have something similar? I know breastfeeding and being post partum can make you irregular.