Did antibiotics stuff up my period for good?!

I was on antibiotics for about 4 months to make my pimples go away. My first period was a year ago. My second was in july last year. And i started the antibiotics after my second period. I havent had another period since. And its been like 7 months. I dont take the antibiotics anymore. Could have they stopped my period forever by ruining my reproductive system. Or am i just freaking out over nothing? Or is it just that i have really irregular periods?