What is more accurate for working out due date?

[Trousersareoverrated]

I know that the ultrasound is the most accurate but that is aaaages away!

My last period was 15th August but we definitely only dtd once anywhere near my ovulation period which was 27th August. So if you calculate from day of conception I am 5 weeks 5 days. But if you calculate from day of last period I am 5wks 3 days.

I know the 2 days are not a big deal but I am just curious- and itching to get to the 6 week mark when I am allowed to self refer to a midwife!

Not sure how you've got 5 weeks 3 days from your period but 5 weeks 5 days from conception as surely period was further away than ovulation?

The day that you DTD won't necessarily be the date you conceived as sperm can last in your body for 5/6 days so could have been after this.

Usually it is calculated from your LMP until you've been scanned. But if you know the date of this and the length of your average cycle I would use the NHS calculator, it's probably the most accurate.

You can self refer before 6 weeks, but they will ask how far along you think you are and will make the appointment based on this

www.nhs.uk/conditions/pregnancy-and-baby/due-date-calculator/

I find tarot cards or a pendulum about as much use.

Don’t worry about it, OP, it’s merely a vague guide.

They'll only ask about LMP when you refer. The first 2 weeks are counted in the 40 weeks of pregnancy anyway which is confusing!This is my second pregnancy and I've never once been asked what date we had sex.

It's impossible to ever know conception date as so erm can like for up to 5 days and a positive opk test simply means you'll likely to ovulate in the next 12-48 hours so you could have dtd 5 days ago but still have sperm ready and a positive opk test but you may not ovulate for 48 hours so really we can only ever work on first day of last period as the conception period in theory can be a 5 day window x

They use your LMP until the scan. But if you know the date you ovulated, take away 2 weeks and use that date will give you the more accurate results.

The calculations are all based on a 28 day cycle, which is the average but not necessarily how long your cycle was. It assumes you ovulate halfway through and then get your period 2 weeks later. If you ovulate late, your baby won't be as developed as the calculation from LMP which can make some people worry (especially as you can be a week out easily!) But it's just a maths issue rather than anything wrong :)

It's kind of pointless. I knew exactly when I ovulated and still they put me a week ahead. If you want to say 6 weeks just refer and they'll tell you what they think anyway