Vvvfl for a week

Hi, I have been using one step pink dye strips each morning for the last week and each have a Vvfl on them and expected it to get stronger but it hasn't. 
I have also felt nauseous and really tired so have convinced myself I am pregnant. Hubby won't believe until he sees it in black and white on a digital I don't think! 
So, has this happened to any of you and if so, we're u pregnant? 
I really just want to know if you can get multiple Vvfl tests and not be pregnant as don't want to get my hopes up? 
Thanks in advance X