How can I tell my friends that I had with my boyfriend?

I'm 16, my boyfriend is also 16 but a grade below me. I had had a crush on him for quite some time and we started dating about nine months ago. After talking about it, we decided to have . We were protected, I am not pregnant, and in fact I couldn't be more elated! is something that should be shared between people who love each other, and I love my boyfriend and my friends know it. I don't have many close close friends, just about four as well as many school-friends. I only want to tell my four closest friends, so how can I go about oding that?