Just wondering if and when periods become or are they suppose to be more regular after birth?

I’m 10 weeks pp, I bled from after birth for about 2 weeks and then 2 weeks later after that I got my first period back for about 8 days (not breastfeeding). I’m expecting my period again this month but nothing yet, lots of cramping to the point it can be painful to walk and lots of back pain as if it’s coming but nothing yet. just wondering if it’s normal to be irregular? I was pretty regular after coming off birth control before we TTC.