Do doctors/MW's ALWAYS calculate due dates from the first day of you last AF?

[anon74]

Have just got a BFP today (yippee!) on CD38 - I know I ovulated on about CD23 and had an implantation bleed on CD32 therefore the first day of my last AF will be wrong in calculating the due date.

Do doctors and midwifes listen to you when you explain this or will they insist on the 'normal' method of calculating the due date - in which case, I will be sent for the 12-week scan about 2 weeks early won't I?

Congratulations! There's no way they can calculate due dates from the 1st day of your last AF. I'm on CD89 today, can you imagine if they timed it from the 1st day of my last AF (If I was pg - which I'm not), I would be 89 days pg!
No, they have to do a dating scan. They had to do this with my DS as I've always had such long epic PCOS cycles.
Make sure they give you a dating scan, YOU KNOW NOTHING!! They dont give scans out very easily!

my date is calculated when I know I ovulated as I miscarried in the month before that.

Congratulations Anon!

Would also be tempted to feign ignorance about date of period. My lot insisted on calculating from that even though I knew when we have conceived. I guess they feel they need to work to a standard, but I found it all a bit bizarre. The only advantage we might have had was that they thought I was due a few days after I actually was, so in the event of going over I wouldn't have been subject to the pressure to be induced quite so soon....

I would be tempted to give them an artificial LMP date or be very very vague about it all - just shrug and say you've got no idea. We have to have IVF/ICSI and there is absolutely no question over when conception occured but still I had to battle it out with the sonographer and antenatal midwife. .

My clinic provided an artificial LMP date but still ... Good grief it was exasperating having to go through a basic lesson in reproduction with them. Shouldn't they know this stuff?