Hi Nova - There is first response HPT's that measure your levels at 20, but there is another one called 'forelife' and it measures at 10, so this would be the better option. I purchased this one at a chemist, and it wasn't too expensive $15 for 3 tests or something like that. It was the 'collection' type. I would try again each morning. You may have just had a late implant and so there is not enough HCG in your urine yet. GL
