Thanks for the advices, my wrist has defifnitely gone better after a week :D
If it was only a one time thing, I wouldnt worry about it. Maybe you bent it too far, maybe your wrist was tired. It could be anything. If the pain is gone, then just keep an eye on it. If you notice any more pain or any swelling, I would see a doctor. It is possible that it could be tendonitis, but since it was only a one time thing and you are not in constant pain, I wouldn't worry too much about it.
It could be just from overuse if you were at the computer for an extended period of time, however, it could also be the beginnings of carpal tunnel. Do you also have any numbness or tingling, especially in like your pinky finger area?
If it continues or gets worse, I would definitely get it checked out - if you can find a hand specialist, that would be your best bet, but any type of orthopedic doc should be able to figure out what's going on.
Best of luck and keep us posted. Oh, and also, in the meantime, try some ice to see if it helps and perhaps even getting one of those wrist wraps or braces tat you can buy at Walmart or any pharmacy and see if that addded support helps.