18 and TTC

I just turned 18 Friday. Last month I had a pregnancy scare, took a test and it was a BFN. My boyfriend then told me he wanted to have a baby, which I'm all for, I've wanted one for the longest time. It was kind of out of the blue that he said that too, last i knew was that he wasn't ready. He doesn't have a job atm, but says he is really serious about TTC. I feel like he doesn't realize how much having a baby costs, and I'm nervous that I'm gonna have to support us all on my own. Any advice on how to get through this?