Having a baby VERY close to SD birthday

My husband and I are finally having a baby (yaaaaaay!) BUT I’ll be having our first baby around a week after his youngest daughters birthday. This makes me feel awful because my train of thought is “oh, great, my child’s birthday won’t be as special and he had sex with his ex to make her around the same time we had sex to make our baby 🙃🙃🙃” (I’m crazy emotional so everything bothers me, literally) I’ve thought about being an evil witch and ditching both of his daughters birthdays just so I don’t have to think about it but again, my hormones are running ragged and I’m probably being crazy irrational. Truthfully, nothing anyone says will make me feel any better right now, I think I’m just venting.