Just so confused

So I had what I thought was a period 10 days ago heavy bleeding as usual so it’s impossible im pregnant, so I did a pregnancy test instead of ovulation test by mistake just didn’t even notice I’d picked the wrong test up. An it came up with a faint line straight away, my wee was approx a 2-3 hour hold. I did another straight after diff urine an negative. It has to be a dodgey test maybe dye run right because I don’t see how it can be positive right ?