All family is planning trip on my due date

Would you be upset or how would you handle this situation?

Let me first say my husband and I run our own grooming business and boarding facility by ourselves and have the best reputation in town for taking such good care of everyone’s pets. We talked with my MIL and were planning for her to help take over so my husband can leave and be at the hospital with me.

Yesterday, my husbands GRANDMOTHER dropped the bomb that everyone is planning to go to Arizona on a trip the week of my due date. Like what?! Why would they plan that? Why would they hide it from us?! This is my husbands first child and basically his whole family is bouncing and saying that babies are never on time we’ll be fine. Their plan is once we tell them I’m in labor she said they will get a plane ticket back home which is a 3 hour flight plus a three hour drive. We have no one else here in town to help us with the shop and worse than that my husband is pretty hurt they planned a family trip that they weren’t even going to tell him about during a pretty important time for us all.

I’m very disappointed and hurt they’d leave us high and dry without planning to even mention it to us. My family loves 6 hours away and can’t plan to be here to help right away... I’m just at a loss.