ovulation testing

Brandi • My name is Brandi and my fiancé`s name is Joe. I`m 23 he`s 25. TTC baby #1. I`m a hair stylist and he`s in flooring.
So I've just started using ovulation tests this month. I took one yesterday and there was a very faint line which I understand to be negative. Today I took another to see if the line was darker and there was no line at all. Has this happened to anyone? These damn ovulation tests are driving me crazy!