18 weeks pregnant but don't feel connected

So, I am 18 weeks pregnant with a little boy. this is my 2nd boy. I can feel him kicking everyday, am going to my prenatal appointments, taking care of myself but I just don't feel connected to this baby. It just doesn't seem real I guess. idk why, and it is really bugging me. I want to be connected and feel attached like I did with my other pregnancy but I'm not feeling that. and it is making me feel like a shitty mom. I just don't know what to do to make it better. Any advice?