Different With Each Pregnancy?

Alright mamas with 2+ kids, I need your help. I am literally the most regular menstruater on the planet. I’m NEVER late. My husband and I have been trying for baby #2 for 6 months and today marks 4 days late for my period. I took a test this morning with first morning urine and it was negative. With my son, I got a BFP 7 days before my missed so I feel like there is no way it would still be negative if I was pregnant.

Here’s my question, was the day you got a BFP different with each child? I know that it could obviously vary, but like over a week different? 😬 help 😭