Am I infertile?!

You guys, I'm kind of freaked out! Maybe I'm overreacting, but I am not pregnant. I've never been pregnant. I've had a few scares but obviously all of them turned out to be nothing. The thing is, almost every woman I know has been pregnant before except me. I'm young, 24, so obviously I'm still in my baby making prime... But no matter how much unprotected sex I have I just do not get pregnant, even on accident. Is that weird?? I wasn't trying before so it wasn't such a big deal but now that I'm sitting back thinking about it I find it strange. My SO and I have been together for almost five years and I was on bc for two of those years but I've been off now for almost a year and still no babies. We just stopped pulling out about 3 or 4 months ago so I know I shouldn't necessarily be too worked up just yet but we've been having unprotected sex for almost the entirety of our relationship and... Nothing... Should i be concerned??