Any of them really. Most work the same.
... like a pregnancy test? I'd use first response. Its a pretty, close to accurate brand.
If.... That's what you're talking about.
First response (: w/ two tests for double assurance!
The dollar store ones actually detect a higher level kg hcg then the more expensive ones. They always work for me ultrasound to 8 days before I.miss my periods.
I used the clear blue with the weeks detector and it was dead on.