Let's be honest

Ronna • SAHM to my amazing 3 year old Princess. Baby Borja #2 on the way. Due 12-31-17
People say they don't get a BFP until after missed period I don't understand that all I would think some of the hormone is there!!! I know you can ovulate late causing it to take time, but if you ovulate around the 14th day of cycle it should show up something right??? How many gotten blank tests and than after a missed period it was Postive!??????