Trying to convince after depo injection

I've bee off the depo just over 3 months now, had some bleeding from the 17th of March until the 28th of March, every calculation I've done has said I'll be ovulating on the 31st of March. I've taken to ovulation tests and it's not even close. I'll add a picture of yesterday's test and when I did today its was even lighter. I'm so confused can anyone help? Please x