I noticed two small dark red blood blisters in my right inner cheeks..i nevr had them before and i don't remember biting my cheeks either. i'm worried.?

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.

Have it checked: Most likely from truma but you should have it checked by your dentist.