white bumps on gums?

my 3.5 month old has been dooling a lot and sucking on his bottom lip along with his hands. today i noticed a white bump on his gums around where his "k9 teeth" would be (the sharps ones) on the right. at first i thought it was a tooth because he also has a rough spot where the tooth would come up.. but i noticed another one beside it and one on the left side but there's no rough spot that made me think it was a tooth... does anyone know if its something to be concerned about?