Do you get self conscious if someone...

Happens to *check you out*?

This happened a few days ago and today. A guy looked at me and kept looking back at me , and while I feel a rush of excitement, I feel so self conscious too. I looked away, both times, When what I really wanted to do was smile. I guess it's my self esteem, which is low. I'll think, 'You're not looking at much buddy' I really wish I could ever feel ok about myself. Do you ever experience that?