17h trip on bus that made 2 rest stops. spent most of the ride with my legs stretched across seat next to me and i fidget alot. could that prevent dvt?

Probably: Keeping the blood circulating in your legs by continually moving them is a good way to prevent DVT.

Activity will help: Activity will help keep your circulation going, and decrease the chance of a DVT. It's always good to get up and stretch, walk around the bus, even if you are stopping periodically at rest stops. best wishes.

DVT: Fidgeting may be better than nothing on such a long trip but not a true substitute for walking around. If completely unable to walk then flex your foot and calves frequently to try and keep blood moving.