math problem

[venapols]

known facts:

LMP: 1st december

cycle length: 27 day average (O on cd14, lp 13 days)

BD: 22nd december (only time)

BFP: 5th january (very very light)



so based on lmp I should be 8w2d
based on BD I should be 7w2d (ovulating late)

however my scan just put me at 5w6d

thats not possible as it would mean I concieved on new years day (well over a week after I had sex) and got my BFP at only 4dpo (seems legit )

ive tried working everything out and at bare minimum I HAVE to be 6w3d (and that date is based on the idea that the sperm survived a whole 6 days and I od 2 whole weeks late both which are highly unlikely + got my BFP at 8dpo)

I know 4 days isnt much but at this stage of growth 4 days is about half a cm difference in size so not something you can miss and a massive difference in implant times

there is a baby and heartbeat that looks good so not a worrying pregnancy

someone check the math, im not crazy right lol

 

[Praying4BB]

I rechecked your math and I agree you should at least be about 6w3d. Though it's not normal for you, I regularly O between CD 22-26, this cycle I O'd on day 23, so it can definitely happen that late and all still work out.

Especially if you saw a baby and a HB, I wouldn't worry too much about a few days, I've seen several posts here about babies that started a little small and then caught up by 12 weeks I bet they can be hard to measure that small too, I noticed my RE taking several measurements during my first ultrasound, all were different, and we obviously went with the biggest ones for each baby I definitely couldn't tell what was shadow and what was baby.

When is your next scan?

 

[venapols]

I rechecked your math and I agree you should at least be about 6w3d. Though it's not normal for you, I regularly O between CD 22-26, this cycle I O'd on day 23, so it can definitely happen that late and all still work out.

Especially if you saw a baby and a HB, I wouldn't worry too much about a few days, I've seen several posts here about babies that started a little small and then caught up by 12 weeks I bet they can be hard to measure that small too, I noticed my RE taking several measurements during my first ultrasound, all were different, and we obviously went with the biggest ones for each baby I definitely couldn't tell what was shadow and what was baby.

When is your next scan?

dont have a date for the next scan but im guessing it will be the 12 week scan, might find out at my midwife appointment next week

 

[Praying4BB]

I would definitely ask for another sooner if you are worried! Hope everything goes well at your apt

 

[hivechild]

Scans that early can easily be a tiny bit off but when you're talking millimeters one way or the other, it can make a big difference. Are you also accounting for the possibility of a late implantation which might affect the numbers.

 

[venapols]

Scans that early can easily be a tiny bit off but when you're talking millimeters one way or the other, it can make a big difference. Are you also accounting for the possibility of a late implantation which might affect the numbers.

if I did implant on say 11dpo (cant implant later than that as I only have a 13 day LP) and say add 2 days for HCG to make it to the urine for the BFP

jan 5 - 2 days - 11 days = 23 december

it would put it at the right time the day after I had sex but I would still be ahead in development and only be off by a day or two right as average implant time that they take into consideration while measuring would be dpo 8 - 10, right?

 

[hivechild]

Sometimes babies are just slow to get started. I know the exact date of "conception" for mine (IVF) but at 7+2, one was measuring at 7 weeks and the other at 6 weeks. By 9+2, the little one had almost caught up in growth.

It's easy to stress and worry about itty bitty details and discrepancies from the norm at this stage, but try to relax. The next ultrasound will hopefully give you a much clearer idea!

 

[AJR14]

Last week my baby was measuring 6+2 with a heartbeat of 122. I should have been about 7. Now 7 days later it grew 10 days worth with a heartbeat of 166. Still a day off bit way better. It can catch up! It could have been the way it was laying or how it was measured. Babies grow at different rates.

 

[MamaBunny2]

Had you been temping or using and OPK? If not then there's really no way to know for sure Perhaps you did O later than usual or there were other factors. As long as your baby is healthy that's all that really matters. I'm a bit confused though... isn't the due date calculated from the first day of your LMP? If so, then that would make you 8 +2 and you would have got your at 5 weeks. I'm thinking you O'd later than you thought. Everyone's different. H&H 9 months!

 

[eventerjj]

At my first scan they I said 7+4 and they said 6 weeks. Since then i have made up 7 of those 10 days. Of you read the U.S. notes, they say plus or minus 2 weeks on the EDD. As you go along you will get a better idea. As an OP said, at that early stage the difference between a few days is millimiters. That could be a twitch of the mouse when they click to measure.

 

[DSemcho]

At my first scan I was supposed to be 6+2 but found out I was 5+3... Then the next scan put me behind by 1 more day. Then my latest scan put me ahead by 3 days.