After we got the call that my second beta had more than doubled, we purchased a box of HPT. I really wanted to see two lines, something we'd never seen before. The first test, the line was faint, but there. I was so excited that it was faint, because then I could see it get darker. So, I waited two days, and took another HPT. The line was defiantly darker! I'm so excited because it means my little lucky charms are hanging on and growing.