TTC & finances

We have been trying for FOUR years... I was 25 years old when we started trying (BF being 27) and nothing...been tracking ovulation, was having sex often - I say was because not getting pregnant has effected our sex life. I feel less than...& he is still just so optimistic. I know there has to be something wrong with me. And when I finally do find out what it is, I’m sure finding a solution will cost a lot of money. We are good right now financially but who really has thousands saved for GETTING pregnant!?