How to make sneak peek at home as accurate as possible?

I’ll be doing my sneak peek tomorrow - it’s the at home test kit. I will be 6+6, which I know is early, but the test claims to be 99.9% accurate from 6 weeks and I just CANNOT possibly wait any longer. 🤣🤣

My real question is, how can I stop my results being contaminated? I have my husband and son at home (I’ll make sure they’re out when I do the test) so does anyone have tips to ensure their dna doesn’t contaminate my kit? And does normal anti-bac surface cleaner work for cleaning down the surface I do it on? Do I need a special spray?

TIA