Is my boyfriend cheating ?

Recently My boyfriends friend  has been hanging with this girl from school and he and My boyfriend went to church with her and she has these friends there. This girl texts My boyfriend all the time but he doesn't really text her back anything but today he went to church alone. Without His friend. The only people he knows there is that girl. And my boyfriend isn't the type of person to go places alone unless he feels comfortable. Last night he convinced me he would never cheat on me. I don't want to freak out for no reason but I feel weird.