Faint positive then a negative? Which is right?

Lacey • Pregnant with #2 🥰

Both clear blue early tests, 4 days late for AF. Took first one in the evening, faint positive. Took the second this morning with FMU, and it's a negative? Which is right? I know false positives are rare, but wouldn't the line be darker in the morning? I'm so confused 😩