Long/irregular Cycles and Due date calculations, help please!

[Apricotta]

Hi, I'm new to all of this. Found out I'm pregnant during the week but can't work out my due date! Every online calculator gives me something different!

I had irregular wacky cycles, possibly due to mild pcos, overweight, sedentary lifestyle (haven't always been, but life had been difficult). Started diet and exercise, lost half a stone and fell pregnant first month of TTC since we stopped because of CV19.

My last few cycles have been around 35 days ish, and the first day of my last period was 7th July. I think I'm 5wks, 5 days in but on websites where it asks you to enter your average cycle it says 4w 4days?!

I self referred to the maternity dept of my local area on Tuesday but haven't heard a peep from them yet, I'm sure they've just been very busy but I'd just like to get an idea on how far I am along?

My cycle is all over the place too and I actually had two "periods" whilst pregnant and only found out I was pregnant due to a turn at work. When they did scan everyone was surprised to find i was estimated 15 weeks from all the msurements. Im just going with date

A gp or midwife will only go off your last period date based on a 28 day cycle until you have your daring scan. So if you have a 35 day cycle it might be that when you have your dating scan they move you back a week. If because of that your scan is a little early they will just get you back in again so I wouldn't worry too much.

I have long cycles, the midwife still used the first day of last period. Then at my dating scan my EDD was adjusted back 6 days.
Wouldn’t worry about it too much now, just go with first day of last period.

Thanks ladies 😊 I'm not worried about it just curious as I don't understand how and why the date changes with cycle length? I guess I'm looking for a scientific reason maybe? I guess it's because I may have had an extra week before ovulation? And obviously I'm super excited and want the baby right now 🤣 🤣 🤣

It changes with cycle length because the amount of time after ovulation you period which is the luteal phase is a pretty consistent 14 days for most women, it so the length of time before ovulation that varies. So with a 35 days cycle you will be about 3 weeks before you ovulate rather than 2 weeks for a standard cycle of 28 days/4 weeks.