Welcome to HCM.
test is nearly 98% accurate. It should be done at least a week from the missed period. As it depends on hCG
, levels can be very low if you do the test early.
If test is done early there will be chances of it being false negative.
I advice you to repeat the test at least week after missed period and also it is better to use the early morning urine sample.
Hope I have provided the information you needed.
Wish you good health.