Thank you again for all your advice again
Guesstimation - that is a good term to describe what they are doing - sometimes I think all this technology is great - but it is a double edged sword - too much information = too much worry - well for some types like mwoa !!
Bathsheba - thanks for the article
I guess weight is not the be all and end all - you only have to consider nappies and how they fit on different bubs etc.. tthere is more to size than weight.
Head circumference on my bub was around 50th percentile - but that could be a guesstimate too

sunshine_sieben - umm my cycles on average would be about 26 days give or take - - I was charting at the time of TTC and reckon we conceived day 13-16 of cycle.
I am a bit neurotic about what my OB said cause I am 160cm tall and pre pregnancy weight of 50kg ...people actually get a surprise when I tell them how much I was at birth - I get a bit of a giggle out of it.

csab - hey thanks I keep up with how you are too xx

Overall I am glad I posted this thread cause I certainly feel more at ease and dont take it to heart...as it looks to me they can get it right or wrong in either direction so guesstimations ...well take them with a grain of salt!!

Anna