have you talked to your doctor about this trip? I'm in the medical field but I'm definitely not a doctor, I would definitely talk to him/her about it. the blood thinners and stretching will reduce your chances of a blood clot, but I'd make sure you got the okay from your doc
that's what I'm nervous about @ginnalynn I take blood thinners for a previous dvt
I drove from Cali to tn at 37 weeks. Definitely doable if you arnt high risk! Lots of pit stops though to stretch and pee and make sure to stay hydrated