Other forms: misgivings
If you have misgivings about something, it means you're worried that it's not a good idea. Trying to fall asleep the night before a test, you might have misgivings about having studied so little.
Misgivings are feelings of doubt you experience about something before you do it. As you get closer to the time you actually get on the airplane, you might begin to have misgivings about traveling far away to go to college, or you might have misgivings about joining the army to pay for your education.