They didn't catch on to the behemoth I was incubating until I was 41 weeks, mainly because I am tall so baby had room to hide. They worked out he was 10lb 9oz the day before I went into labour, but reassured me they always measured bigger.
He was 10lb 10oz when he was born two days later.
Just get them to talk through the realities of delivering a big baby so you can decide what your real options are.
In exactly the same situation! Saw consultant this week who basically said throw the tape measure away. He felt my bump and has confirmed baby is a good size and if it hasn't appeared by my due date they'll start to encourage it along (sweep etc).
I'd wait until the growth scan before worrying too much. In this pregnancy I had two consecutive massive measurements which were shown to be spurious at scan, which put baby back onto 75th centile (a rather more manageable 8lbs). Bizarrely every tape measurement since has confirmed this, as did the 2nd growth scan. Must have been having a podgy couple of weeks....
I'm concerned about this, my last ds was 9ibs (an increase of 2.7ibs to my previous ds) and I measured normal with him so it wasn't picked up, as I'm relatively small framed he got stuck. I'm now having my 3rd ds, and had my first measure yest at nearly 28wks and I already measure 2wks ahead. He feels a lot bigger then ds2 did at this point when he moves around. So really worried. And midwife told me same procedure will still remain, sweep at 41wk and induced at 2wk over, which scares me I went over 2wk with ds1 (6ib 8) and ds2 was on time. So really worried about going over xx