I woke up with an odd feeling in my cheek. it feels a bit swollen, & inside, i see 3 small red marks.did i bite my cheek? did something bad bite me?

See your dentist: The most common type of dental pain and swelling is a tooth pains, and the second most common is a gums infection or combination of both tooth-gum problem. In order to get appropriate treatment it is important to know the underlying cause for this pain. Rec.: see your dentist for evaluation, x-rays and treatment. Very common and treatable.

Good guess but....: Yes, your guess about you biting your cheek is a very likely one, but without personally examining you, there's no way to know for sure. Wait it out and see if it goes away within a few days to a week or see a dentist just to be sure.