As a pregnant first time Mum to be, I have stressed over every result too!
Ireckon we get so caught up in the little details we forget the big picture- yor bub is growing and moving and happy.
If you think about us, none of us from children to adults would measure exactly right either! I mean I have a little head. I mean, I am tall 1.7, size 12, but fit kids hats, have done all my life!! Oh and to reassure you I am reasonably intelligent with that too- have a uni degree etc LOL!!