Irregular periods and EDD

[LadyFarnborough]

I have irregular periods, last one started on 23 Jan.
I got a positive OPK on 1 Mar. So really should be about 5 weeks pregnant.
I've been to the doctor today, he's based my EDD on my last period date, so now I'm just over 8 weeks pregnant according to that.
Presumably my 12 week scan is going to be too early? If they revise my dates do I get another scan at the right time? I'm in my late 30s so a little higher risk, I want to make sure I don't miss out on the nuchal scan because I go too early

If you're scan is too early they won't be able to get all the measurements they need so will definitely book another one for you. Doctors have to go from LMP as thats the only sure thing they have to go on.

Thank you. Well I guess the upside is an early scan to know everything is ok and real!

I had this with both pregnancies... And in both pregnancies ended up with a scan date at what turned out to be 7/8 weeks... Had those scans and then they rebooked scans for when they believe 12wks to be based on foetus' size... All good!

thank you

I have really irregular periods. I had quite a lot of scans at the beginning to determine how far gone I was. My first scan (should have been 7 weeks by dates) showed me to only be measuring 5 weeks so I was asking to come back a week later to check that the baby was viable and growing. Thankfully a week later I was measuring 6 weeks. I had a 10 week scan and one at 12 weeks too as well as the 20 week one. They moved my dates around a bit though - first it was the 6th june, then 16th june, now they've settled on 12th june :)

I have a condition which means untreated I don't have periods at all. With both my DSs I have conceived the first month / 6 weeks of treatment. With both of them I was sent for a scan when they estimated I would be around 12 weeks according to when I took the pregnancy test but they did say I would be rescanned if way out.