Don't want to hurt my parent's feelings but that's just how it is

Cassity • Laila 05/15/17, Xander 4/10/18, and Grace 11/06/2019

I'm 18 weeks and STILL haven't found out if I'm having a little boy or girl. IT'S KILLING ME!! Anyways I go in two weeks to find out. My mom (step-mom) is going with my husband and I and my dad will probably want to go too since its his first biological grandkid. My stepbrother has had 2 kids but my dad is excited that his biological kid is having a baby if that makes sense. The problem is that I have a prenatal appointment on the 10th (which is a Friday)and then on that day I'll schedule my ultrasound for the following week. But I don't know if my husband will have enough time to take the day off from work. If that's the case my parents will be the ones taking me since I don't drive. BUT if my husband can't go then my parents are NOT allowed to go in the ultrasound room and won't be able to find out the gender until after my husband finds out. Because I'm almost halfway done my pregnancy and my husband hasn't even gotten to see the baby once and has only been to one appointment while my parents have gone to every ultrasound and every appointment. I'm so worried that it's going to hurt their feelings because they seem even more excited than I am to find out (if that's even possible. I don't know how to tell them and I know they're gonna try to argue with me. But I'm not gonna have my husband miss it while my parents get to be there since they've gotten to be there every single time. He feels left out and it's his kid so he definitely shouldn't be. I'm gonna try to make it at the end of the week so he has time to take off from work. But if I can't I'm so worried to have to tell my parents no and then have to fight with them.