Braxton hicks triggers?

Any other mommas have their Braxton hicks triggered by driving? I had a baby doctor appointment today for our growth scan and it's a little over an hour drive there just one way and I swear every time I get home I'm exhausted and hurting terribly and seem to have more Braxton hicks. I'm 31 weeks today and everything was fine. It just makes me paranoid can't help it lol my back is killing me tonight now.