silly question

[SJ BROWN]

Just read Marteens thread about flying and 1 of the replies was about flying at 6 weeks(4 weeks after ec/et)<br><br>I have always wondered how they calculate how far gone you are. (being positive!-we will all need to know this wont we!!)<br>My illogical brain would say that 4 weeks after et you would be 4 weeks,, the same as if you conceived naturally I would work it from after AF. AM I making sense. <br>WHy then do the experts add time on. How can you be 6 weeks if the embies were only tansferred 4 weeks ago !!!! and if you conceived naturally they always work the time back to before AF-DUh!!!!! Am I a donut cos I cant work it out. <br>I know its not important but its something I have always wondered & am just curious....<br><br>Anyone know??<br><br>Take care everyone<br>SArah xx

[Jules R]

Hi Sarah<br><br>It's not a silly question at all. If you get pregnant naturally, they work out your due date as being 40 weeks after the date of your last period. So in other words by the time you ovulate and conceive, you are already 2 weeks pregnant which is very silly! Obviously because of all of the drugs etc we don't have normal periods at IVF time so they work out the 'pretend' date of your last period as 2 weeks before EC or ET (depending on the clinic) so again by the time you have EC, you are supposedly 2 weeks pregnant. It's all really to make the figures nice and round - 40 weeks/9 months as opposed to 38 weeks/8 1/2 months - and because most people can't give a definite date that they conceived but it is a strange way of doing things. The only good thing about it is that you don't actually have to go through 9 months of pregnancy, if you see what I mean. This probably isn't at all clear but it may help.<br><br>Jules

[SJ BROWN]

Thanks for that....<br><br>Like you say though "SILLY" or what!!<br><br>Have a good day, <br><br>seems to be getting a bit cooler now....<br><br>Sarah <br>xx