BFN today :-(

Brittany • Mommy to a wonderful 12yr old boy, 9yr old boy 7yr old girl 6yr old girl and 3yr old girl. Due March 11th 2023 with a boy.
Got a BFN today. I was so sure I was pregnant. I just don't understand how you don't get pregnant when your ovulating an constantly have sperm inside you :-/ so frustrating.