Like what everybody else has said, just refuse the test if you don't want to do it. My DS1 was 4.1kg, DS2 was 4.7kg (No GD either time). Both boys were overdue and quite puffy when they were born. DD this year was a tiny 3.8kgs. I did a growth scan around 30 something weeks and she was in the 40th% at the time (cue, Magnum ice-creams au-go-go from that point onwards A GP I saw last year said that some hospitals freak out if a baby is over 4kgs, but they're still normal. Nothing new there!
I hope you start feeling a bit more supported