Confused with boyfriend

Me and my boyfriend have been dating for 3 months and we've been doing really good. He gave me the password to his social media accounts because he really wants me to trust him and I go through it every once in a while. Today I went on his Instagram and one of his old friends, who moved, was dming him. She used to like him but I guess he didn't like her back. She asked ," how are you and your gf?" He replied " we are doing alright I guess" I don't know if I'm overreacting or not. I feel like he should've responded with something like ," oh yeah we are doing good." What do y'all think?