So I just had a back tooth removed Monday and it's Thursday.  I had to go back to the dentist to get some fillings today and told my dentist about it.  I was afraid I had dry socket.   He said it was normal, not to fret if there isn't severe pain or throbbing pain.  He gave a look over a said food gets trapper in the hole and can't get out so it's best you gargle lightly at first and the after a few days you can use mouthwash to gargle to dislodge the food.