Confused

[tomtom875]

Hello Annie

I just confused bout an issue killing me lol.im currently pregnant and my last period was June 14, I had unprotected sex with my bf on June 24/25 and he came inside me both times.on July 3rd I had sex with a friend and used a condom which I know didn't break,my due date is est at 3/21/14,on August 14th I had an ultrasound that says the gestational age of d fetus was 8weeks and 5days,is there even a chance that guy b cld be d dad?

[AnnieBrooke]

Back in mom's day or grandma's, a woman who was pregnant only had one clue, her period stopping coming.  She'd go to the doc, and he would ask, "What was the first day of your last period?"  Everything about the count of pregnancy was then calibrated to that date.  They didn't have ultrasounds, they didn't have hCG tests, so they would just begin the count with the big, obvious signal that the first day of bleeding was such-and-such.  The doc was not saying she got pregnant on day 1 of her period, but a start point was needed in order to understand how the pregnancy was progressing compared to average.

All medical counting is still done that way.  With the advances of science, maybe some day it will not, but the first day of the last period is counted as the first day of gestational age.  

Obviously, this is not a very accurate way to count, since not all women ovulate on day 14 after bleeding begins.  Some women with irregular periods can ovulate 30 or 60 days after the first day of their last period, and others ovulate as early as day 8.

So, if a doctor does an ultrasound, and the woman says her last period began on January 1, but the measurements of the embryo strongly suggest its development began earlier or later than January 14, the doctor will go with what the ultrasound says when computing a due date.  Again, this is so the pregnancy can be calibrated to other pregnancies and understood as it progresses.

Pregnancy from GA to due date is considered to take 280 days.  It is considered to take 266 days from ovulation to due date.  That extra 14 days is to count back to her first day of last period, or to the implied first day of last period if the ultrasound disagrees with the woman's report of when her period was.  

The main measurement of the embryo is the crow-to-rump length, and they look at other markers also.  After a while, some babies grow faster than others, but in the first few weeks of pregnancy, measuring that way is pretty exact.  The margin for error grows larger with time.

[tomtom875]

Hello Annie ,another question,I heard u talk bout measurements of fetus or gestational age and all,I just wanna know,how are they measured,is it based on fetus growth and how is lmp used when in fact at lmp,one isn't actually pregnant yet,just wanna know bout this things,cause u seem to be easy to talk to here,bless your heart

[tomtom875]

Thanks Annie I thought as much,I really know deep in my heart it's d boyfriend being he really did ejaculate in me,the friend I know the condom was very accurate and didn't break,it's just my guilty conscience killing me I cheated on my bf,thanks a lot 4 answering though

[AnnieBrooke]

Here is what the conception calculator says based on your due date.  An ultrasound in your eighth week would be either be accurate or have just one or two days' margin for error at most.

     First day of last menstrual period:  June 14
     Probable date of ovulation:  June 28
     Possible dates of conception:  June 24 to July 2

     Due date:  March 21 (40 weeks)

Given that the unprotected sex with your boyfriend would have put a lot of sperm into your reproductive tract that would have remained fertile for a while, and since you used a condom with the other guy and it would have been just after your possible conception window, the chances are much stronger that the baby is your boyfriend's.  I would go ahead on that assumption, but at some point after the baby is born I would probably do an over-the-counter DNA test with the friend or the boyfriend just to put the question entirely to rest.