I have two small dark red blood blisters on my right inner cheeks. i never had them before and i don't remember biting my cheek either. they are not painful at all. help.

See a dentist: If the blood blisters resolve in a 2 week period. Most likely you will be fine. If they persist, then have your dentist look at them. You probably got them from biting or from eating sharp/hard foods.

See a dentist: They are probably heamtoma's related to cheek biting. If you don't remember, you could have done it in your sleep. You should have it checked by a dentist to be sure.

Likely local trauma: It is most likely local trauma from the teeth but should be examined by a doctor to ensure nothing else is going on. There are viral illnesses and other local infections/masses that can present this way and a good exam will hopefully exclude anything serious.