it probably is! i had a vaginal delivery and got mine 28 days after birth. scary & crazy at the same time, thinking that it would've been possible to become pregnant again so quickly (i'm single though, so no worries...) and that my body is like a clock... come on really, after 28 days on the spot!? didn't expect that at all since i'm also bf'ing, but exclusively expressing, so i guess that's the difference!