Should I break up with my best friends?

I have two best friends. One guy and one girl. The girl I have known since freshman year of high school. The guy I have known since junior year of high school. I joined a sorority while on campus so I was a bit distracted going out and meeting new people. I also admittedly am not the best at long distance relationships... but being that this is now the summer after my first year away at college, I find it so strange they are ignoring me now that I am back home. I feel like they don't care about me and have moved on to find other bestfriends. Been home for nearly a month and still no response from them. Is this a momentary silent treatment or a sign our friendships are done for?