OPKs. Digital Vs Test Strips?!

Suzana
Hello I was just wanting some opinions on digital opks vs the strips...
I have been testing with Both 2x a day around 1 pm and late evening. how ever last evening I got a flashing smiley face on the digital and vvvvfl on the strip... Same for today except the strip is showing a bit more than yesterday. Do the digitals pick up more than the strips? Just confused and want to make sure we do the deed on the right days...