Rant, rant, rant

I had my first iui done may 20th so I have to test June 3rd. The wait is killing me. I've taken so many negative pregnancy test, and I'm so scared I'm going to be so disappointed when I go to test again. And we don't have the money for another iui. My sister got pregnant 3 months after her and boyfriend got together. I've been with my husband for 7 years!!! It's not fair. And to top it off she's 2 years younger then me. I'm only 23. I'm trying to stay positive, but it's really hard.....