Ultrasound measurment behind when compaired to LMP

[nma85]

My LMP was somewhere around 8-1 and I got a faint + hpt on sept 1st. I usually have somewhat long cycles ranging from 33 to 38 days. I have no history of pregnancy loss and this is my 3rd pregnancy. I had a dating scan yesterday and according to lmp I had calculated that I was around 7 weeks 2-3 days. However the ultrasound showed only a gestational sack measuring 5 weeks with a yolk sack no embryo. The tech assured me that everything looked normal and that I was probably just off on dates but there is a 2 weeks difference. I'm supposed to go back in 8-12 days to check for growth. I'm terrified that something is not right!  I have two questions one, is it normal for an ultrasound to be so off, from my lmp putting me at 7 weeks and only measuring 5 weeks? Second my first positive was very faint and they have progessively gotten darker. I took another test yesterday and my urine was almost clear, very diluted and the test again was very dark ( test line far darker than the control line) If things in fact stopped growing 2 weeks ago ( at 5 weeks) would I still be getting such dark positive tests? Thanks for any input! I sitll have yet to hear back form my doctor and I'm going crazy with worry!

[nma85]

Thanks for your response as well! I have a tendacy to freak out when it comes to these sort of things!  I've never had an ultrasound this early, previous pregnancies were at 11 and then 13 weeks so it was a little discouraging not to see a heartbeat! I called yesterday after the u/s and spoke to the med assist. and asked about having blood work done and she assured me that the dr would call with the new u/s date and that bloodwork was not neccisary. I feel like calling and demanding blood work! At least that would ease my mind a bit until the next u/s. *sigh*

[nma85]

Thank you for the response! In looking to dates I guess that would make sense being that I should have ovulated sometime during the week of 8-16. I just wish the dr would at least call with some sort of information! Thanks again!

[smjmekg]

I agree with alaysha. It is entirely possible that you ovulated later than you may have thought, and since you already have longer cycles you aren't going to be as far as off your LMP. You ovulate about 14 days before your next period, and going off LMP they assume you have a 28 day cycle. Then after fertilization it can take 6-12 days before the egg implants and starts producing HCG to show up positive on a test. It's possible you were at the latter end of the time frame with this baby, and that would make sense to why the measurement is off...even the early u/s can be off by a little bit, not for sure how much so I don't want to say a week when it's really only three-five days...but they can be off. With this pregnancy (now 29 weeks) I was measuring 10 weeks 4 or 6 days, at 11 weeks 1 day based off my LMP. So I was a little behind, and then at my next ultrasound at almost 22 weeks baby was measuring right on schedule off my LMP, and I have irregular longer cycles too.

[alaysha]

If your cycles are longer its possible you ovulated late and are only 5 weeks along which is where Id placs my bet. But to answer your question it is completely possible to have miscarried and still show positive on a test. My first pregnancy the baby stopped developing at 6 weeks I didnt find out until I was supposed to be 9 weeks and had to get a d&c to remove everything and even then didnt stop showing + on a test for 4 more weeks. So 7 weeks still showing positive after baby stopped developing. But like I said before I think youre really only 5 weeks since you didnt show positive until 3 weeks ago and you tack 2 weeks on top of that which would give you a date of 5 weeks.