What do I do if my boyfriend of three years doesn't want to have kids?

My boyfriend and I have been together for around five years, while we only started dating for three. He's nearing his thirty fourth birthday this year and I'll be twenty two this summer, he has two kids from two separate ex wives and his son lives with us. He says he wants more kids but he refuses to have any right now. I know its early for me but I've dreampt of being a mom for years, I have Rh Negative blood which makes it very difficult for me to conceive and carry past the first trimester without blood transfusions and strict health routines. I love this man with everything I have and I was well aware of his previous marriages and the children he has from them before I moved in with him. The problem is that I feel like our time limit is running out because of his age and my fertility issue... I've had this discussion with him multiple times and heard the exact same excuse each time. "I want kids, but not right now. Maybe in a few months or a few years, I don't know." I don't know what to do. I have to force myself not to let him come in me in his sleep (he has Sexomnia, a condition where he has sex in his sleep without waking up.) and not to show him how much it kills me inside to feel like this. I'm severely concerned about our relationship and its stability, I really need some help. Any ideas or suggestions would be greatly appreciated.

Firstly, let's correctively tell it like it is: You and your boyfriend have not been together for around five years because for the first two there was a completely different kettle of fish in-situ, called FRIENDSHIP. So you were Not Very Close for 2 years and then discarded that basis for Quite Close (With A View), meaning, your boyfriend and you have been together for three years. And aren't even married. Neither does his particular age count for much. Men stay fertile practically their whole lives. Look what principles and self- and child-protective measures you're prepared to sacrifice in order to overcome this fear of yours. You're panicking. And you wouldn't have to force yourself to do ANYTHING if you would accept the fact that the guy doesn't want them enough to give you even any realistic timeframe (or proper answer full-stop). I.e. there's a huge difference between a few months and a few years. And 'maybe' means 'I don't know'. So that's 'I don't know', plus a nonsensical sentance, plus another 'I don't know'. Equals, 'I don't know, I don't know'. HOWEVER!... It strikes me as rather odd, to say the least, that this guy who's so 'baby-shy' would night after night risk impregnating you! Think about it: if you were him, with his (hmm - forensic psychiatry's still divided over whether Sexmania's real or not) 'condition', wouldn't you, following the usual wide-awake naughties, propose that one of you then sleep in a separate room? So that an accident CAN'T happen? And why do you assume he can't work out the very simple fact of how utterly desperate this 'can but can't' situation is making you? Who are you dating - Forrest Gump? You're not, are you. So what is he - playing Russian Roulette with your womb? If the overwhelming majority of FPs et al are correct, in that, Sexmania IS a pile of self-serving nonsense then wouldn't that make what he's nightly doing a case of horribly teasing you? Emotionally torturing you, even? (I mean - it does, doesn't it.) How do you know - for a fact, I mean - that he has "Sexmania"? Did his GP/Consultant tell you? Or just him? Food for thought? I think you DO know what you have to do but are paralysed against action because you don't know whether ending the relationship or sticking with it (despite the nightly torture) is the safer option. Correct?