Need some girl advice

So, my bf n I have hit a bit of a rocky patch in our relationship. We've had a few in the months we've been together. But for about this past month, I've noticed he's being a bit distant with me n not really wanting much to do with me. He's never wanting to be at home with me. (He used to always want to be around me n at home). Constantly leaving me alone n gone for days. (We live with his mom n she leaves a lot for business, n he goes with her)Takes longer to reply to my messages as well. Am I overreacting or should I be worried?