Kind of upset...

My boyfriend an I are not in the same city area in the summer. He graduated from college in 2014 and I am just going to be a junior this fall, anyways, I just feel so far from him and I feel like he isn't missing me at all. I miss him a lot but he rarely says he misses me. Idk why it's been bugging me but it has, I just feel kind of small to him right now. Idk though... It may be his way of coping with us not seeing each other but it just feels different than las summer when he would attempt to call me every chance he got or send me cute texts. Should I be upset or am I overthinking?