Here's a known fact: Everyone around you sees you 20% more beautiful than you see yourself. They stare at you because you are beautiful and womanly and attractive- as all women are!
Don't bring yourself down honey, it makes you seem urging for attention! Just go with it and don't wait till your friends say that cute guy is looking your way- try to be confident and maybe even go talk to him first. Men love confident, bold women, so be one!
Maybe you're just entering that age when guys are starting to notice you!
Girls going through puberty will obviously feel and know about their bodies changing, but because it can be gradual, it doesn't seem like such a big deal.
But when guys start noticing how you're developing, trust me, they will think it's a big deal. So that might be why they stare.
Also, it sounds to me like you must be very pretty for all these guys to be staring like that. Either that or the guys in your school are all very rude for staring!!