Nope, it's not bad that you're not married at 21. I was married at 18.... have 2 wonderful kids from that marriage... but the husband.. well not so much... then at 37 I got remarried and have 2 wonderful kids from this wonderful man.
My older kids are 27 and 30 and neither one of them are married yet. They're not in any rush either. My 30 year old is engaged, but again, she's not in any rush!
So just enjoy yourself, and when you're ready to get married you'll know.. :)