I accidently took my diabetes medicine twice in 4 hours i'm supposed to take it twice a day and i took it three times?

Depends on medicines: There are different types of diabetes rxs. Depending on which particular rx was taken excessively -- a person may have later risks of low glucose (hypoglycemia). For common rxs such as metformin and pioglitazone, an isolated extra dose will not cause problems. For Insulin or sulfonylureas (glipizide, glimepirude) -- these may cause hypoglycemia later -- will need to follow glucoses to see.