What Are The Red Bumps On The Arm After A TB Test?

hello, i got my tb test a week ago and it came out negative. however, the same day there were bumps on my arm. it increased and its on the same arm as my tb test and its on the under side of my arm. the last time i got a tb test back in october, it was negative and i had no other bumps or any other reaction after it. they dont itch or anything. some are red but thats about it. there are no other bumps anywhere...what is this and what should i do to get rid of it?