5 month old possible ear infection?

What is the best way to distinguish between teething and an ear infection? My daughter is 5 months old and she has been teething for a while now. The last couple of weeks have been extremely bad though, she has become my permanent attachment :) She is not happy doing anything anymore, will not play in bouncer or activity center, does not want to lay down and roll on the floor. She pulls on her ears sometimes but that can also be from teething right? She is not running a fever, I just checked and it was 99.3 which is pretty normal for a newborn. She has not been eating like she normallly does and she is still sleeping pretty well but occasionally will wake up more than she normally does. I do not want to rush her to the ER just to be told that she is teething. I thought I would ask other mothers who have had children with ear infections the best way to distinguish. I would appreciate any help you could give :) Thank you.