Is it possible to have positive and then negative?

Bianca • 🩺👩‍⚕️

I had faint positive hpt at 10dpo then even darker line at 11dpo. then 12 dpo i took a test and it was negative!? All the same brand test and all fmu. The lines were not indents they were pink. I’m so confused now I thought i was pregnant🤷🏼‍♀️