White bumps in mouth?

had two white bumps in my mouth... they didnt hurt they were very small and only around for like 3 days... then i got a bump on the floor of my mouth on the outside of my gums and it was white circle shaped n was painful but it only lasted like 2 days then left but is stilla little red. I also notice a nother white spot but it also isnt painful. Im wondering is it my tooth brush or infection or canker sores? Like a week before i had two little bumps filled with fluid and i burst them ive had these since i was little .. I have even been tested for and I am clean (just because of an annual check up) so what culd it be?