Little Sad One, I want to have a talk with you because your post is very poignant, and it tugged my heart strings.
I think you are very young and just plain too young to enjoy all the urgency, messiness and lack of "refinement" in having sex with a persistent teenage boy. If a girl is not ready, as maturity level, to deal with sex, it is a very unpleasant way to pass the time.
I know having a boyfriend is the most important thing for a high school girl....but.....having sex too young will have negative consequences later on in your life when you would be ready to explore your sexuality as a more mature person. Right now, sex is going to become misery for you. That kind of association will be hard to overcome in the future.
I have to say this....the best thing is to break up with your boyfriend.....a sadder but wiser girl, but a girl who made the right decision...and knows this in her heart.
Very, very best wishes in 2008.