Not had a positive ovulation test!!!!

Emma

So it's my 5th month off the birth control pill an even no I came off it i still had my normal periods an I was even getting positive ovulation test right away to but I worked out I was only getting them on cd18 but last month I get it on cd17 so I didn't take my first test this month until cd16 an it was negative an I've been taking 4.5 tests day an still negative.. I've even done one about an hour ago an that was 99% negative were there wasn't even I got of a second line.. So I'm thinking cuz it's been 5month off pill an I have a 28.29 day cycle could it be were my body is back to it's self an I maybe ovulation on cd13 or cd14 as that's when I should be ovulateing on with my cycle anyway I'm very confused????