Am I antisocial? Or just carefull?

I have quite a bit of friends. I am 14 (going into 9th grade this fall). During school, we are really cool and stuff, but after school or during summer break (like right now) most of them don't even bother calling or texting. most of them don't even have a facebook. one of my friends, well, she is pretty much the only person who always asks me to hang out with her. i'm ok with that, except it gets kind of embarassing when my parents realize that everytime i'm going to "hang out"- i'm just going to her house, so i have started to make up excuses every time she wants me to hang out with her. I have no idea what my friends do over the summer because most of them aren't even going on vacation! None of them have sisters either. some of them go to church and make friends and hang out with them, but i don't go to church. i'm just kind of picky with friends in general and who i hang out with, but when it comes to be that they NEVER ask me to hang out, or i ask them to hang out and they make an excuse, i feel lonely and spend my day playing with my little brother or spend literally 10 hours of my day eating or using the computer.