The method you used is bio-impedance. It shoots a little electricity through your body and it bounces off the fat i nyour body. How long it takes to come out is how much body fat you have.
This is a HIGHLY flawed test. The results are rarely accurate. The amount of fluid in your body can throw the test off - if you are fully hydrated it is a little closer, but if you are even A LITTLE under-hydrated, it will be off.
I am not saying you are not 10%, but a female at 10% is VERY VERY lean. At this BF%, you would likely have a few abs sticking out, if not a 6 pack. You should be able to see serious muscle definition in your arms, probably back and legs too.
I'd stick with calipers, Bod Pod, or hydrostatic.