I'm confused with these tests??

Rio
Ok so these are opks, about 12 this afternoon I took this test which came out a strong positive? 
Then this reallllly negative test just now!? Wtfs going on?? 😂😂 the positive is a Asda one and I'm starting to think there faulty because last month I used them too and got positives for 5 days straight! Anyone shed some light ?? Thankyou xxxx

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