Travel 12 hours secretly pregnant

Sasha • First time mommy with a brand new beautiful baby girl!! 😻😻
Hey ladies just a quick question. Im 15+2 with my first child. My family is planning a 12 hour road trip for next week. Me and my husband are attempting to wait until fathers day to announce it to everyone. Im not showing alot so thats not the issue. Im just not sure if i can "mask" my preggy symptoms for 12 hours and 5 days away from my normal life/environment. Any ideas? Hubby says we should announce before the road trip but i think its kinda rushed. Any ideas on what i should do or how i would cope in a car for 12 hours?