I know you said you don't want to hear this, but really, you should say no.
A) no method of birth control is 100% reliable. None.
B) if he doesn't want to wear a condom, he's immature. And if he thinks pulling out will do the trick, he's an fool. It does not work.
C) if you're not willing to accep being pregnant, you shouldn't have sex. Period.
That said, if you insist on having sex anyway, then insist on him wearing a condom. I don't care what his reasons for not wanting to are; if he cares about you at all, he will do it. And no matter what you think, if you believe you are going to have sex in the near future, you better seriously start thinking about a visit to the clinic for some bc pills.
I admire you for at least coming here and looking for advice... At least you just aren't saying "screw it" and running out to have sex anyway. But, seriously, please think about this before you do it. And .D.O.N'.T let him pressure you into .A.N.Y.T.H.I.N.G!!!!!!!!!!!!!!