I have two very painful lumps on my right armpit. They seem to be under the skin, they're definitely not pimples--much bigger than that. They've been there for a couple days. I've read that they could be swollen lymph nodes but I think that would mean my lymph nodes in other areas would also be swollen? I also read that it could be breast cancer which is obviously worrisome. Anyone have any idea why they could be?