Late ovulation - working out weeks and dates - help needed

[KM86]

I am approx 8 weeks BUT my last period was the 26th June,
I hit my LH peak on the 11th July and "think" we conceived on the 12th/13th
I have a 28 day cycle but ovulate on CD17

First pos test was July 21st

Please can someone help me work out how many weeks I am roughly! My head is hurting from trying too!

We are having an early scan Saturday

Thank you!x

I would say you are 7+6. You could be 8+0 if you managed to ovulate on the 11th instead but I would lean towards you ovulating on the 12th July.

So you do Ovulation day -2 weeks for an estimated LMP. Of course it can still be a few days off if you ended up implanting early/late.

Your period is fairly close to the estimated LMP anyway so you would likely be fine with it.

In my last pregnancy I ovulated 6 days later than my usual, and my usual is already later than the average day 14. So I did estimate my LMP then and it was fairly accurate. 2 days out. I ovulated on day 24 and the typical is day 14.

Don't the midwives calculate from first day of your last period? That's what all mine were. If so it would make you 8+1 scan only differs few days anyway. Congratulations 🎊 🩷🩵

They do until the scan then it goes on measurements.
My cycles are long (40-45 days) so LMP wasn't accurate for me. I am 2 weeks behind what I would be with LMP because of the late ovulation

thank you - I know the growth would essentially then be 5 days "behind" wouldn't it? I reckon 7wk 3 days BUT going off my period it would be 8+1

It so confusing! Its all an estimate but I want to make sure the midwifes etc don't panic that we're not growing at the right speed etc

The LMP date is just the starting point and based on an average 28 day cycle with ovulation on day 14. Most women are probably within a few days of that so keep that date but some are well out of that range.

My first early scan was 8 weeks from LMP but baby only measured 6 weeks, I went back 2 weeks later and growth is exactly 2 weeks as it should be. It's literally just down to when I ovulate.
My due date has been calculated on these measurements, not on LMP

If you ovulated on 12 July then you are 7w5d today (not 7w6d as 15dpo = 4w0d).

If you know your ovulation date then LMP is meaningless. LMP is used as a ‘best fit’ indicator because the majority of women don’t know when the ovulated.

Also, if you know when you ovulated then you can ‘tweak’ the day of your LMP to make it fit. This will ensure you get called to scans etc at the right time! (Assign ovulation day as CD14 and work backwards to CD1)

Thank you all!

I really wouldn't worry at this stage. The measurements at your stage are so tiny, they won't be accurate. Best to wait til 12 week scan which is a better estimate. And it's always an estimate, don't get too hung up on the estimated due date! it can work both ways though, I ovulate around day 17/18 but my current pregnancy has been measuring bang on date in line with my actual LMP.