Pregnancy Test

I did a pregnancy test on 12/14 but it was negative. After we shopped at Burlington Coat Factory (we were looking for snow pants, snow boots, beanies, and gloves for Ethan and Wyatt), I wanted to stop by 99 Cents Store and pick up another pregnancy test. I was about to buy two since I didn't think it would be positive. I took the test right away after I got home. Eric was asking me, "What does two lines mean?".