Different results in two different brands for pvulation testing

I had 3 consecutive positives for lh on the 15, 16, 17th of this month. I tested today with target brand and it came out positive again...but I tested with "answer" brand and it came out negative... what the hell is going on...also...my temperature never changed...not then...not now... I'm veru confused and wondering if I missed my ovulation period this month... what do I do now??