FR Ovulation Test - Dark test line, no ref line

I took a First Response ovulation test. Directions say the test line needs to be as dark or darker than the reference line. On two tests on Friday and Saturday, my test came out with a really dark test line but murky shadowy area where the reference line should be. We had sex Saturday. Then last night, two clear dark lines for both test and reference. Hubs went out of town for work and we didn't have sex.