First time

So me and my boyfriend are both 15 and his 16th birthday will be the day after mine. He’s really eager to have sex as soon as possible (literally after school on his birthday) and at first I was to but now I’m not so sure. I love him and want him to be my first but part of me just wonders if it’ll be too soon. Anyone have any ideas as to how I could talk to him about my concerns knowing he’s so eager? Would love to hear any advice?