No their not after 37 weeks. My waters went at 36+6 and had I had him that day he would have been classed as prem. Only problem was they didn't alter his wee red book to reflect that he was born at 37 weeks so I had a bit of a battle with the midwives regarding weight as they were plotting him from EDD but the HV staff nurse came out, took the page out and plotted him from 37 weeks gestation, which helped a little but he was still a little thing.
I had a growth scan week past Monday and this one is estimated in 10th percentile so they're scanning me again on Monday as it's a little small but if she was born next Thursday at same stage as her brother she'd probably weight about the same as he did. I was scanned and checked at 36 weeks as I thought I was in labour with my son and they told me that I had a huge baby, 6 days later I gave birth to a small baby so it's not all that acurate!