Can anyone help me work out due date?

[Cheeser]

Hello! I got pregnant in the first month since stopping the pill and I really am not sure how to work out my due date.

The last day I took the pill was Sunday 8th October. Do I class Monday 9th as the first day of my cycle? I didn't get a withdrawal bleed but did later have what I thought was a period on Nov 4-7 but it was odd, very very light and not normal menstrual bleeding for me so I thought it might have been implantation bleed - and in fact prompted me to do a home pregnancy test which was positive. DP and I only had (unprotected) sex once that month, on 26th Oct.

Is that information alone enough to work out due date? I have seen the GP to 'book in' and will meet my midwife and have what GP has estimated as 12 week scan both on 10 Jan. He didn't seem to know how to work it out though and used some kind of rotating wheel thing but he didn't give me a due date when i asked him. I know it doesn't matter much, I am definitely pregnant and will find out more re dates etc at the scan, but it would be nice to know so I can work out how big the foetus is, what is developing week to week etc.

How do you work it out if you haven't got a first day of last period to work from? I usually have a 28 day cycle.

Hope someone can help!

Hmmm. Not sure there's any sure way to work it out for sure until you have your scan and they can date the pregnancy - when they measure the baby they adjust the 'gestational age'.

Cycles are dictated by ovulation, so it would all depend on when your body decided to ovulate - you don't need a period if you are coming off the pill, your body just 'kick starts' ovulation when it's ready. If you had a positive test during or shortly after the bleed it wouldn't have been a period, much more likely something to do with the pregnancy.

So if you had sex once around 26th Oct you would have ovulated on that day or a few days after, and if you normally have a 28 day cycle, the 'beginning' of your cycle would be about 12 October, in that case, giving you a due date of about 4 July. The GP's calculations make the date a couple of weeks later if he's counting 12 weeks as 10 Jan, somewhere around 3rd week of July I think.

When you book in, can you ask the midwife for an earlier scan to date the pregnancy? It would be a shame to go for what you thought was a 12 week scan, only to find you were a couple of weeks further on than you thought - they can only do nuchal measurements up to 13+6, after which the baby is too big. A few ladies on here have been given 12 week scans for the wrong dates and then couldn't have the nuchal transparency test (if you are not bothered by this it matters less).

HTH

Thanks for responding HPG, everything you say makes sense. So that makes me 6+6.

I have my booking in appointment on the same day as my scan is booked - I now won't see anyone until 10th Jan. When I saw the GP he asked me some questions about my lifestyle, took my weight and gave me that Emma's Diary thing. Then I got a letter from the surgery confirming an appointment with the midwife on the morning of 10th Jan, and a scan at the local hospital in the afternoon of the same day - so I won't get the chance to have anything done sooner.

That means I'll be 12+6 when I have the scan, I think.

Do you think it's worth me ringing the midwife unit at local hospital to try and bring it forward, or is that ok? This is my first pregnancy and not really sure what to do/who to contact.

I would contact midwife directly. Mine told me they need the 'booking in bloods by 9/10 weeks.

Thanks pomme. What do i do if I don't have the midwife's details? I haven't met a midwife yet. Do I just call the midwife unit at the hospital that I've been assigned to? Will call them this afternoon, see what they say

Right just phoned the midwife unit and they said so long as they see me between 11 and 14 weeks then that's fine. She was very helpful and friendly which is a good sign . She said they aim to do booking in and scan together and that it's fine, and my dates sound ok. Phew.

Can start worrying about something else now