Don't worry too much, J.. Your body will probably take a while to return to normal, and it might even settle down into a new normal. Before I had kids, my period was every 28 or 30 days for 3-5 days. I was NEVER late or early. Never. Now, two babies (and one miscarriage) later, my body has settled down into it's usual 28-30 day cycle, but occasionally I'm late (as much as a week) and once I was early and my periods last up to 8 days (a few heavy days, then a day with no bleeding, then drizzling for a few more days). It's different, but I think that may be a normal experience for women. Give yourself at least 6 months to a year before you start getting worried that something is wrong with you. Your hormones are all over the place just having a baby around you (even if you're not breastfeeding), so things may not stabilize right away.
Good luck with that new little one!
J. B