Why does my arm hurt?

I just turned 21, and had a party last night. Of course, I got drunk, which was actually my first time ever getting fully inebriated. However, I woke up today with a usual hangover, but my left arm is in terrible pain. The muscles feel tight, and it’s throbbing rather irregularly. As I mentioned before, I don’t drink alcohol in excessive amounts, so I don’t think it could be anything like alcoholic neuropathy. I’m sure I’m just psyching myself out, but has any ever experienced this who doesn’t drink that often?