boyfriend troubles

So my boyfriend and I recently moved and one of his good friends who is a girl is now living in the same town as us. I recently have been noticing that they are texting a lot and hanging out more than usual and when they aren't hanging out she is always brought up somehow in conversation!. The one day that him and I had off together this last week, he wanted to hang out with her later on that day! I am really starting I second guess their relationship, and thinking that maybe I am doing something wrong and he could be starting to like her more than me. WHAT THE HELL DO I DO?!!!!