How do you afford it?

When I was 14-17 I had one period a year. I was put on birth control to regulate it and it did. I got off birth control when I was 19. Periods stayed normal until last year. I went 4 months without a period. Picked back up normal until beginning of this year. I've had a period for January and February and March and April. May I had just brown old blood. I haven't had one since then and that was it. Last year when I didn't have a period, I went to the dr. They said I was pregnant. Which I wasn't. That was that. Went to the dr earlier this year. Not pregnant. This past time I had a Pap smear and all that and she said she wanted to pull blood for hormone imbalances. Each time I went to the dr it was $100. I couldn't check my hormones because it was going to be right at $500 for it all. I don't have health insurance and I can't pay to figure out what's wrong with me. What can I do? I want to know what's wrong with me but I can't afford it? What can I do?!