very confused as to gestation age and conception dates

[thisisjuno]

Hello,
I am 28 and pregnant for the first time. Heres the issue at hand:
LMP March 27th
first doctors appt: May 13th..HCG levels 7,698 on this date
second doctors appt May 19th...HCG levels 32,304 on this date

My question is how accurate is using the LMP because according to my doctor I should be around 7 weeks and I had a vaginal sonogram on May 19th (this past MOnday) and there is a normal sac, a fetal pole and a length of 2MM. I was immediately sent to another facility with better machines and was told I may not be as far along as they thought according to my ovulations dates. First place still says I should be further if my LMP was def March 27th...which it was. If I conceived around April 15th I wouldnt possibly be 7 weeks even if LMP was march 27th would I. Am I missing something. Am I at risk for misscarrage. My next appt is in 2 weeks. No bleeding whatsoever...thanks...

[nikko*ttc]

By the way, How long is your normal cycle?

[nikko*ttc]

Maybe you ovulated later than normal. Keep your chin up and I'll pray that the next scan is better. I've m/c twice so if you need anything just let me know.

[thisisjuno]

ya thats what I am afraid of. I am definately not showing to be 8 or even 7 weeks pregnant. According to my levels and ultrasound, Im at most 5 weeks. That is why they think something might be wrong. Second doctor made it sound like it might be ok though and that its common. I am going to try and bump my appt back a little to see what is going on. I def haven had my period since march 27th...

[nikko*ttc]

Okay, I believe my LMP was March 29th. Confirmed pg on May 6th, and I go next tuesday for an ultrasound to date pregnancy and to make sure everything is okay since I have m/c twice. I am almost always a 30 day cycle. So, I am guessing that I am around 7 weeks as well. It sounds like 7 weeks would be just about right for you as well, seeing as our LMP is only 2 days from each other. What makes you think they might be off? I think the common error is usually a few days to less than a week. So, it is possible you might be 8 weeks or even 6 weeks, they'll be able to tell more as the baby grows. At your next appointment hopefully you'll get to see (and maybe hear if they do transvaginal) the heartbeat.

[spade22]

LMP is NOT accurate in a number of cases because women can ovulate at any time during her cycle, and gestational age based on LMP assumes a women ovulates 2 weeks after her last period.  When the latter is not the case, gestational age is essentially date of conception minus two weeks and is usually deduced from an ultrasound (which can be off by as much as a week too but tends to be much more accurate during the first trimester).  If you conceived  on April 15th, gestational age would  begin on April 1st (2 weeks prior) and gestational age would be 7 weeks and 2 days as of today.  If the dating was based on your LMP then you would be closer to the 8 week mark.