Confused!

Hey! So I have just come of my pill recently when my last cycle finished! My period always came like clockwork ( I assume it was because i Hav been on the pill for 8 years) I am using clear blue digital ovulation kit I had no high fertility days and then on day 10 of my cycle I had a peak? Would this be correct? I took another ovulation kit a supermarket brand on the same day and it came up negative I am nt sure what is going on?