Help! Lines are disappearing

My lines have gotten lighter over the last couple days and I’m afraid I’m going to miscarry. My sleep cycle has been a bit funky the last couple nights not sure if that’s why my lines are disappearing. Does anyone have any experience with this? If it did end in miscarriage how long after your lines started fading did the miscarriage occur? Anyone have lines that got lighter then darker again? Any feedback is appreciated I’m a little on edge and just want to see those beautiful dark lines.