Ovulation (clear blue digital help)

Carly • I am 32 and from Southampton in UK. Me and my oh are TTC baby number one. Had miscarriage in January 2015.
Hi ladies I am really confused. Hoping someone could let me know their opinion. I have been using clear blue digital ovulation sticks. The ones that give you the flashy smiley when high fertility and then the static smiley when at peak. Well yesterday morning I got a flasher so me and oh dtd. However I ran out of sticks so I went and got some more only the ones I got this time are the same but you don't get a flasher. They only give you blank circle for low fertility or the static smiley. This morning I took another and it was blank. Any ideas? Wonder if I ovulated last night now or should keep testing? Thanks