Mommies, when did your monthly period resume after childbirth? I am breastfeeding (pero mix formula Na si baby). Thanks!

HI, I had a baby through C-Section and my doctor told me that she has cleaned my uterus, so I got my periods after 45 days or so. Even though I was breastfeeding I had my periods quite unexpectedly within 45 days, as I know women who do not have their periods till a year.