Positive clear blue but negative other brands

[Rainy2]

I recently took a clear blue test which was faintly positive but a pale blue line nevertheless. I’ve then got 3 further positives on clear blue tests but all other brands have been negative. I’m so confused. I haven’t had a period in 18months but I had symptoms of ovulation about 2–3 weeks ago now.
any advice would be so appreciated

How long did you leave the tests before you got the blue line? They all look like classic Clearblue evap lines (thin) so would be
negatives. Best bet is to get some pink dye tests and go by them. Hope you get the answer
you want!