TTC and the hardships of it

I'm only 21, I'll be 22 this year. I have many years that are still healthy to try and get pregnant. Every time the little screen shows up with only one line, I get so discouraged. Like something is wrong with me. Babe keeps telling me I'm still young and have plenty of time. He wants kids. What if I can't give him that? I feel so awful about it. I've had sore breasts all day and now little minor cramps. I had a two day period last week. I don't want to test because I don't want another negative. What should I do? What should I expect if it is early pregnancy? Idk. Help :(