Husband wants kids, but doesn't want anything to do with fertility treatments.

So I have PCOS, and my husband and I have been trying for 17 months to get pregnant. We have seen an OB about the pcos, and she said we can try ultrasounds/bloodwork to see if I am actually ovulating (I am getting positive OPKs), we could try clomid or other things. I desperately want a kid, and he says he wants kids. But he isn't willing to move forward with anything, and he won't let me be on birth control in the meantime (I figure it'd be emotionally easier to have no chance of getting pregnant then to have a chance and have my hopes get dashed every month). It's so frustrating... I don't know how he could want kids but not let me go in for an ultrasound (100% covered by insurance, so it's not a money thing). Augh. I'm so tired of having arguments with him about it. I've waited 17 months, but that's still not long enough for him to want to do anything about it. Any advice? What do I do?? So frustrated..