Sex While TTC

So my husband and I have been together for 12 years. I can say in these 12 years, our sex life has had its ups and downs. He has never been one to want it ALL the time. But it seems like lately, he practically never wants it. And honestly, I can't blame him. We have been officially TTC for 3 years now. Before then, we were not actually trying but if it happened, it happened you know? Well now that we are 3 years into this thing and there is still no baby (or a pregnancy period), the sex has gotten down right boring, repetitive, and just no fun at all. I feel like we are only doing it because we want a baby, thus it isn't very enjoyable anymore. We are basically just going through the motions. It has come to a point that we hardly ever try during my ovulation window anymore. Does anyone feel like me? If so, you do you cope with it? If not, what do you do to keep your sex life exciting? I have been wanting a baby for so long and I am disappointed month after month. I am beginning to fear it will never happen for me.