Glow due date and my doc information not corresponding!! Help !!

Camille

My last period was on January 5th, my ovulation peaked on January 23 there about.....Glow calculated my pregnancy to be 8 wks 3 days but went to my doc and it appeared its younger...no heart beat and the embryo seems avout 5 wks plus....im not sad and confused...as to whats happening. Anybody else can relate ? Im confused as to how far i am in pregnancy or is there a problem with my embryo growing....as this ever happen to anyone.