Ever since about 7 months pp when I got fat af, my period has been wacky, when before pregnancy and…

Ever since about 7 months pp when I got fat af, my period has been wacky, when before pregnancy and a little after it’s always been right on time since I first got it. I’m like 3 weeks late and I could with be pregnant or my fatness is messing with my hormones again. My doctor literally told me I have to loose weight or this will keep happening