8 weeks, ? about gestational sac

Seagull2012

Hi all -

Well, i'm chugging along at 8 weeks pregnant today. At the u/s everything looked great with the baby - right on track, heartbeat around 140 (she didn't measure but "guessed" and i read online 140 is actually kinda low for 8 weeks so i'm hoping that it was actually more like 149, which is minimum for 8 weeks), and we even saw the baby wiggle and his arms/legs are developing! The Crown to Rump length was 15.6, which RE said is normal for 8wks +/- 3days so looks like i'm in the average, if not a bit low, range.

The only concern is that the sac size is still on the small size (note this was an issue at 6wks, though we saw a hb and fetal pole, then). My RE then said this was b/c it was a FET and they tend to run a bit smaller. The sac was measuring 6wks 4days +/- 7 days, so optimistically let's say it's about 7wks, 4days -- 2 days behind what i'm actually pregnant. Saying it like that doesn't sound so bad but then if i think it's actually more like 6wks 4days makes me worry it's a week behind!

My RE wasn't concerned about the sac at all, saying that sac size measurements at this stage of pregnancy really vary and don't really matter that much. The important thing was strong heartbeat, wiggling baby and significant growth.

I was in a great mood leaving the u/s but, thanks to Dr. Google, now i'm worried about the sac size and, of course, that the baby could stop developing all of a sudden. But i guess that could happen at any time. 

Any girls on here have small sac size in comparison to weeks pregnant? Note i'm looking for reassuring stories here b/c i found my fill on the internet of scary ones!

Thanks

We are super grateful for making it this far. Next u/s (and hopefully our RE "graduation") is 12/21.