Advice!

Ellena
I need help with ovulation tests! 
I have last two days had 2 lines on my cheapie ovulation tests from Amazon. They were taken last night about 8:30 & then 8:30 this morning. 
I took my clear blue test this morning but I got a blank circle?! 
Please can someone help me out?! Are these not positive or what could be going on?! 
Thanks