Same urine 3 ovulation tests 3 different responses low, high chance, and smiley solid

So that title says it all i did three tests at the same time same sample the first holder is the oldest the flashing smiley face is a week old and a brand new holder gave me low chance. Which one is correct? My flow app said that today was the best chance to get pregnant. I have been having trouble conceiving and had an operation 5 weeks ago to help. I have had many flashy smiley face over the last 4 weeks day after day then a low chance then the next day back to flashy face. We have had sex every second day and we made sure we took every smiley flashy face seriously and the same with the solid smiley face. I just want to know which test i should put my faith in? My OBGYN says if i dont fall pregnant in the next 4 weeks we have to get IVF done. So please any clarity around these results would be appreciated.