My son is 13 month, he is teething and on the bottom right hand side his gums are swollen where a tooth could be trying to come through. The other three teeth came through without a problem and this one seems to just stay swollen like pea size or smaller. It hasn't seemed to be bothering him til last night/today. I don't know if I should take him in or not. It doesn't seem red as infected, there hasn't been any pus or anything like that. It's going on 3 weeks it's been swollen and all his others have can through and this seems to be the last one. I get more and more worried as hours go by. He has no fever, ad okay appetite, normal dirty diapers,