Just need some advice

So I almost had sex for the first time last night and I deffenetly did not plan to or want to me and my boyfriend have been "dating" for over a month and I deffenetly do not think that's long enough he's the same age as me (15) but he's had sex before he attempted to put it in and I just can't get over the fact that he would do that so soon when he knows I'm a virgin and it makes me think that sec is no big deal to him or maybe he was just so turned on he couldn't help it he apologized after and seemed really embarrassed and we just layed there and talked I don't understand why I'm worried so much or what I'm worried about