Boyfriend and his female friends?

Im 20 and I have a pretty amazing boyfriend of abt 5 months and he treats me well. He has a lot of female friends though and if hes not talking abt one its about the other. Especially this one of his friends he constantly chatting with her. Even when we are together, hes texting her, on the phone with her, when we are shopping hes on the phone with her. Yes he tells me abt it he doesnt hide it from what i know it platonic and they all know abt me but it just gets really annoying and i dont want to be the annoying jealous gf so i dont say much abt it i just change my demeanor so he knows its bothering me. and when i do say something he just throws it to the side like its not a valid feeling. Should i not be feeling this way? Should i talk to him more abt it or just drop it?