Shy guys paranoia

Lately I have been a bit paranoid. No, not about the government taking me away at night but girls. In my English 12 class I will be doing my work when I get a strange feeling that someone is watching me and so I take a quick glance around the classroom. Sure enough, a girl from across the room is staring in my direction but quickly takes notice of this and turns away. It happens quite often and I catch her on a regular basis doing so. Also, she will try to spark a conversation with me whenever things get quiet, wear my jacket when I am not, or copy my homework when I leave it lying around. Even if she did like me, its not that I don't like her, its that I am rather shy and frankly I don't need to be getting in any relationship now because of my financial status, parents(mother is weird about me having a girlfriend), and a group of friends who may tease.
This is not the only occasion when stuff like this happens. I was at a vending machine buying some coffee when I noticed a young Asian girl purposely trip and grab hold of me. That same girl is always talking to me and I have no clue what her name is still. I get this even at the grocery store where the cashier told me that she would tell Karen that I stopped by. I told her I did not know a Karen but she insisted that we were very fond of each other.
I am not sure what this feeling is because I don't regularly have this happen to me as I avoid social interaction with new people. Usually I keep my nose in the books or on the computer in my spare time but this has been driving me crazy to the point that I can nolonger concentrate in school. I've got a feeling that all this new attention is because of all the training I've been doing with my personal trainer in the gym. Now that I have become much more filled out in the upper body I have been feeling much more confident about myself and am nolonger insecure about wearing short sleeve shirts.
****Well its pretty late so I must finish up physics work and fill out applications for jobs since mine is slow at the moment.****