ovulation test help!

according to glow I am suppose to ovulate the 16th (3 days from now) I have target brand tests and it says it will read positive if you are expected to ovulate in the next 24-48 hrs. took one today and it was negative as expected. I  also bought first response tests today and they are suppose to show positive if you are going to ovulate within the next 3 days but it came up negative also. in the instructions it has a chart figuring when I should be ovulating it says the 14th! anyone else test negative when they are suppose to be ovulating?