I had 2 c/s for frank breech

and had never experienced any labour until my third birth, which was my first uc. I had prodromal labour every night for four weeks, during which time my water broke twice (sealed up after the first time and then just leaked after the second time a week before the big final day), and the massive amount of adhesions inside my body tore and healed.
On the day that our uc ds was born, it was 44 weeks and 2 days since conception. I had been unsure initially of the date, but there were only two possible ones and when the first one passed three months earlier (I hadn't had a visible cycle then for years, so no reason to even suspect I was pg), I could easily count the time. I measured 46cm.
My second uc was at 42wks, 3days, and may have gone longer but I hadn't eaten in two days and had a terrible flu (as did our three boys), so I had suspected I would go into labour with all that wretching and no food.
I couldn't care any less what the averages say for how long my gestation should be. My babes were active all the way through, responsive and alert in the womb, and I am very intimately aware of them.
My concerns don't include length of gestation on the later end of pregnancy. My only concerns about dates happen on the early side.

ETA: I personally wouldn't consider sweeping or getting help just for dates, ever. If I was concerned about the health of the baby, I would try other methods first.