Sneak peek experience?

I am pregnant again with a baby due in September, when I was 8 weeks I decided to use sneak peek (I live in the UK). When taking the test my 13 month old son was downstairs but I had been cuddling him in the morning/stroking his hear etc but thought I had throughly washed my hands etc. I also bled quite a lot so had to run to the bathroom and use the tap (husband uses) then ran under my nails. I know it was stupid.

Anyway my result came back a boy but now I’m wondering whether to believe it or whether it could have got contaminated - would it really be that sensitive?

Just wondering if anyone has an experience/knows others with experience of these tests?

Thanks!