Relax, everyone is a virgin until the are not, you are not alone.
Well if you go around telling them all. Duh
Not if u don't tell em
You don't have to tell them...
If they aren't a virgin, they might know if you are, ba<x>sed on how you flirt, etc. / moves. Or they might think you are just shy or gentleman-like/proper.
It's easy to tell. Just be honest and don't be ashamed by it. Some girls will actually like you for it and maybe even bang you just because :D