My arm fell asleep while my husband drove us home last night. its been 12 hours and its still asleep. i didn't sleep on it weird. is it normal?

Arm falling asleep: 12 hours is definitely a long time to regain normal feeling to the arm. What do you mean exactly by "falling asleep." Does your arm feel numb? pins/needles? weakness?, does the arm feel colder? Any swelling when compared to the other arm? If that is the case you should go see a doctor. He/she should check your pulses and possibly do an ultrasound to evaluate for a venous clot (DVT).