On Wednesday I had a filling on my furthest back tooth and obviously i had an injection for the procedure. It didnt really hurt when I had the injection but the next day the pain started. My mum said it was probably just a bruised gum but it has also swollen up a fair bit to the point whew when i bite down i keep catching the gum. Ive been taking painkillers to deal with the pain but its been going on for 4 days now and is showing no signs of healing.