Relationship advice

Me and my ex partner recently broke up due to a pregnancy scare, we've been together on and off for just under a year! But basically we've not been together for a month or so but we are still having sex, I'm worried he's using me for sex! Also the fact that we don't use protection, mostly because I'm allergic to latex and it's expensive to by latex free, I'm worried about my chance of pregnancy! Please mind that I'm 15 going on 16 and unable to work due to a medical reason! So basically my question is how to I ask if he actually wants to be together or not! I want it to be suttle and not to forward because I don't want to seem pushy! Helppp