Sorry, I've no personal experience... I've yet to have a normal period since my LO was born - but I've been on loestrine BC for well over a year-- my few friends that had that after LO didn't seem to have anything "out of the ordinary"- and trust me, we converse about the subject- LOL. But one was BF for months- so she just got her period back, the other always had irregular periods. Personally, I always had a very regular period- even before LO when I was on the pill... so that kinda freaked me out, but all is normal.
If you have concerns- I'd speak with your OB. But honestly, it can take several months for hormones and such to get back to normal- so I'd try not to worry for now and just give it some more time and see...