I'm scared to have sex

I mean it's not that I'm scared but I don't know if I'm ready I kinda would rather start doing it when I'm in my own house or something at least , paying my doctor bill because I'm a very private person. I'm 18. Me and this boy been talking for months now and if I become his gf he's going to want to have sex, doesn't every guy?  Even tho I could honestly tell him I'm not ready im just very picky on situations like that. I feel like that's what he really wants though and i want to do it just to get it over with honestly the pressure is so annoying so what y'all think?