Can anyone explain a 19dpo bfn?

Sal • One 💙, one 👼🏻, one 🌈 🎀, by ovulation induction after 2 failed IVF cycles 🤯 | Hypothyroidism & lean pcos 🤨

Hi all! Reaching far and wide for help. As you can see from my chart I am 19dpo but still getting bfn on FRER using fmu. Did anyone on here have this experience with your pregnancy?? Thank you!