Darker lines?

Madison • 🦄👩🏻‍🎤🌸 Hufflepuff | it’s nice to be important, it’s important to be nice |

Is there a chance that a darker line on an hpt very early DPO means and that there could be multiple's. They run in my family and I tested at 10 DPO. My lines just seem very dark compared with everybody else that I've seen testing at this date.