Long cycles affecting the reason for measuring behind?

[dano99]

Hi

I had a scan at 7 weeks but measured 5. The scan showed everything was right place just measuring smaller than lmp and no heartbeat yet. My cycles have varied about 30-35 days long in the past. Could this be the reason? I got my positive test on day 29 of my cycle

It was for me. I have always been about a week behind my lmp date which I knew I would be because OH was away with work a lot when we were ttc so I knew the exact weekend it happened. I am now 30 weeks.

My cycle was around 33 days. Midwife was convinced I would be 6+4 when they sent me for an ectopic rule out. I told them I was sure I was nearer 5+4 due to my cycle length. And sure enough, I measured at 5+4

It was for me. In my second pregnancy, I just lied about the date of the start of my period so it would match up to their 28 day cycle and I was bang on.

I would imagine so - I have 22-23 day cycles and measured 5 days ahead at 12 weeks so assume it works the same way in the opposite direction IYSWIM!

Also the same for me! Went for my 12 week scan last week and measured at 10 weeks, which is what I expected as my cycle length is varied - mostly 28 days sometimes 35 days. Thar particular cycle I'd seen the relevent mucus a lot later than I normally would (didn't use ovulation kits) and I didn't get a positive test until two weeks after when I would have had my period if on a 28 day cycle. Baby on scan had a strong heart beat and was very active so sonographer said it was likely that and had no concerns :)