PCOS and one night stand

[Kellskel]

Hi

I am currently 18w 5d pregnant. I had my 1st ultrasound on Nov 25th which said I was 10w 3d with a due date of 6/20. I had a second ultrasound on Dec 7th that dated me at 12w 5d with a due date of 6/16. I have PCOS and have very irregular periods that don't come for months at a time. I had sex with my ex on 9/22 using the pull out method, my boyfriend and I were also actively having sex everyday to every other day. I was in the hospital from 9/26-9/30 which is what conception dates I am getting from online calculators. I had a blood pregnancy test on 9/26 which was negative. I am so nervous that my ex could possibly be the father but not sure seeing as to how my periods are EXTREMELY irregular and we have no exact LMP date to go by just ultrasound dating! Please help!!!!!

[Kellskel]

Hello, just wanted to inform you my results from Ravgen came back and my current BF is the father not my ex! I'm super relieved although $1400 later I must say it's worth it for a piece of mind! I would definitely refer anyone neededinf answers to them the staff was extremely knowledgeable and supportive! Thank you!!

[AnnieBrooke]

I'll bet you are so delighted!  Congratulations! and I'm glad to hear that the Ravgen staff were so good.

[Kellskel]

I had my 3rd ultrasound Friday which I was 19weeks 3days by that ultrasound and she also said my due date was 6/20, does this put my boyfriend at a higher chance of being the father? Also I had a DNAtest through Ravgen on Wednesday as well so I'm hoping it correlates with my boyfriend I'm so stressed and worried

[AnnieBrooke]

Unfortunately, later ultrasound information is not helpful for pinpointing conception because of the variable possible growth rate of babies.  Your first ultrasound would be the only one to use, and even it was too late to pinpoint things as closely as you needed it to be pinpointed. The later the ultrasound the more wide the possible margin for error (if trying to use it to date conception).  I'm glad you got a DNA test done, or you would be asking and asking with every subsequent ultrasound, and no later ultrasound will help.

Your original dates suggest you ovulated near the time the first guy's sperm in your system would have become non-viable. Your DNA test will show whether this is true and the second guy is the dad.  Be sure to write back!

[Kellskel]

So I'm assuming for conception on the 22nd blood work on the 26th definitely would be too soon?

[Kellskel]

Sorry I understand what you said in reference to conception and implantation. I had some days in October around the 21st of bleeding which I thought was possibly a period so I was thinking I conceived possibly closer to the end of Sept or beginning of Oct.

[AnnieBrooke]

Bleeding happens for a lot of reasons in pregnancy, that aren't periods.  Let your ultrasounds be your guide in ruling out getting pregnant in October.

[AnnieBrooke]

Timing wise, both men are possible.  I assume all the sex was unprotected?

Something that does not make a difference is that you used "pulling out."  Pre-ejaculatory fluid comes out as soon as a guy gets an erection, and if the guy had an ejaculation prior to having sex with you, sperm could have been in the fluid. It only takes 1.

Something else that doesn't matter is that you were in the hospital from September 26-30.  Sperm can live up to 5 or 6 days in your reproductive tract.  This means you could have had live sperm from both men in your tubes when in the hospital, ovulated when you were there, and conceived without even having sex that day.

So the question is how reliable the scans were.  Were the two ultrasound places equally good?  I don't suppose you had any that were earlier than the ones you mentioned?

Failing that, you could spend the big bucks and get a prenatal DNA test from Ravgen or the DDC, or you could simply assume that since you had lots of sex involving ejaculation with your boyfriend and only the one encounter with your ex, it's more likely to be your boyfriend's baby.

[Kellskel]

The first ultrasound I had was at 10w 3D. The first one I had at a radiology center they don't specialize in prenatal ultrasound. The second one I had was at a prenatal center. All the encounters were unprotected. Since I do not have a normal cycle and there is no way to tell exactly when I ovulated how accurate could my scans be? I am having a DNA test through Ravgen this week but wanted another opinion before unfortunately shelling out those big bucks. Also does the blood test I had on the 26th make any difference? My ex is aware of this situation so he will actually be going with me to have the test done, I didn't tell my current boyfriend so I was advised to bring in discreet sampling using his toothbrush. I'm extremely nervous but hoping since my cycles are irregular and I was active with my current boyfriend pretty much everyday that he is the father.

[Kellskel]

I also have an anatomy scan this coming Friday. Although I'll be a few days over 19 weeks not sure how accurate that will be.

[AnnieBrooke]

You're using the word "accurate."  Ultrasounds are very accurate for what they are designed to do, which is, look at things inside the body.  Your baby's anatomy scan will certainly be accurate, it will show what they want to see in your baby's body.  Don't worry about that.

Ultrasound information is not as helpful for pinpointing conception as you need, because you had the ultrasound too far along in your pregnancy.  Some embryos grow faster, slower or at an average rate. There is no way for a doctor to know if your particular baby is growing faster, slower or average by looking at one ultrasound, or even two (especially when the two were done at different places). An embryo does grow at a known rate for a while, but after the sixth or seventh week, you would have to compute in a margin for error if using ultrasound data to try to guess when conception was.  By week 12, the margin for error is +/- 7 days, according to most doctors, and by week 40, it is +/- 3 weeks.  This means that, given the dates of your ultrasounds, you can't know for hundred-percent sure who the dad is unless you get a DNA test, and your later ultrasounds will have bigger possible margins for error if you try to use them to assess when conception was.  I would never consider the data from an 18th week ultrasound reliable for that purpose.

Regarding your blood test on the 26th, hCG only goes into your bloodstream after the embryo has implanted.  That doesn't happen for 5 or 6 days after conception.  If you conceived on or around the 26th, the pregnancy would not show up even in a blood test for another 8 to 10 days at the earliest.