It can generally take anywhere from 4-16 weeks for menstruation to begin again.
I don't know if you are on any method of BC, but keep in mind you could become pregnant and then your period won't return. Some woman's cycles will change after pregnancy, while others stay with how it was after. If you don't start this month, then do follow up with your doctor as he/she may want to jump start your cycle.
Best of luck and congrats on the baby as well. Hope this helps, If you need anything else please feel free to ask. If you found this helpful don’t forget to click the *ACCEPT* button and leave *POSITIVE* feedback.