Due date is May 29 but doctor says I’m 15 weeks and 4 days

Stacie • Mommy to an Angel 08.08.18 expecting Rainbow Baby in May2019 💕

So I had a miscarriage in August and found out I was pregnant again in September. Doctor says my due date is May 29 but instead of being 15 weeks and 1 day he says I’m 15 weeks and 4 days. Anybody else?