I had a little breakthrough spotting at around 2 months, when the twins were getting supplements, but once we got them back on the boob completely, it went away.
Then it happened again around 7 months, when they got really into solids and cut back on their nursing. (Both of them took to solid food easily and got really into it.) Once the initial thrill wore off, they went back to mostly nursing, and the spotting stopped.
Then at just past 10 months I nightweaned DD2, and started cutting back on the night nursing with DS. I had a few months of odd periods, that were really short and light. I think they were probably anovulatory, since the twins were still nursing at least 8 times a day each.
Then at 16 months I weaned completely, because I needed to get back on meds and was really debilitated. Anyway, it was about two months more of the short, light periods, and then when they were 18 months, I started having periods that were normal for me. I think that once I got back on my meds, I could maintain my body weight better, and so I was able to menstruate normally.