It'[s not unusual to get varying test results. As Motherofan18month suggested, I would take another test first thing in the morning with more concentrated urine! Good luck!
take another test with fmu (first pee of the morning) the hcg (pregnancy hormone) has to have at least 4 hours to build itself back up so when you get up in the morning you need to test again! best of luck! keep us posted on how things go!