It really just depends. Every woman is different. First off, it can change by how long you bleed for right after delivery. Also, if you are breastfeeding, that can change your cycle a lot. Some women don't even have periods while they breastfeed, or very light ones. Me personally, I bled for about 5 weeks after my delivery ( I had a c section), and then had my first period about 40 days after that. The next couple periods after that came right on time, though.