First, good luck to everyone taking MCAT in two days! I had a bad experience of not being able to fall asleep the night before April MCAT. I am really afraid if the same thing will happen tomorrow. As a result, I just bought 'diphenhydramine hydrochloride', a common sleep aid in case I have difficulty falling asleep again. I have never taken sleep aid in my entire life so I don't know how I would feel the next morning. Anyone ever used it?