How accurate is the ultrasound scan in determining conception dates. Soo Confused

[Aldior]

Hi, I have a worry. I had sex with my girlfriend on 17th November 2014. She called me on 14th December 2014 telling me that she has missed her periods. I was so confused and worried as we had agreed not to have a child at this time. I wanted to confirm that she was actually pregnant, so we went to hospital for a test and it turned positive. However, when she was asked when she had her last periods, she said it was 20th October 2014. From the calculations, it was not adding up. We were referred to another doctor for an ultrasound scan. We went there the following day which was 23rd December 2014. The results of the ultrasound indicated that she was 13weeks and 2days pregnant. Can it be possible that I impregnated her? What am I supposed to believe? Am I the dad? Am soo confused. Please help.

[Aldior]

I now understand you pretty well. Thanks for your time and advice. I still maintain that I only had sex with her on the two mentioned dates. Then I was still getting to know her better, may be that explains the two encounters for sex. But I must say am humbled by your insights.

[AnnieBrooke]

Sorry, this is getting kind of hypothetical.  Or was this story about last year and the baby was born on July 19?

You had sex, let's see, in August and in November.  (Since that time span is unusually wide for only two sexual events between a boyfriend and girlfriend unless you have been physically apart, in your shoes, I would double-check those dates and be sure you really did only have sex twice, three months apart.)  

Anyway, what you have now is that she says she got pregnant by you, and the doctor says she was in her 13th week around December 23, and you can't make that add up to either date when you had sex.  That's all the data you are apparently going to get until you get a DNA test, as you say you don't even have any way to double-check what the doctor said by getting another scan.

If she got pregnant by you on August 16, she should have the baby by the first week of May if she does not go over the expected due date.  If that date comes and goes and she is still comfortably pregnant for quite a while after it, then all you have left to worry about is the sex you had in November, which would produce a baby due around August 9 if full term.

But if the baby arrives earlier than August 9, that does not rule out that it could be yours.  It is not like it is unusual for a baby to be born early.  I suppose a baby born in the 36th week of pregnancy is technically premature, but that does not mean it won't be born then if it came from the sex in November.  Babies can be born in their 24th week and still survive.  (It takes a lot of medical effort for that to happen, but it is possible.)

In short, don't assume you are not the dad if the baby arrives on July 19.  Just have the DNA test done (by a reliable lab, certified by the courts for properly handling the samples and determining paternity.  Don't use a drugstore test.)  

One of the prices men pay for getting free sex from their girlfriends in this day and age (unlike grandpa, who would have thought he had died and gone to heaven to have so much available sex) is that sometimes they have to get a DNA test.  In the overall scheme of things, that is a pretty small price to pay.

[Aldior]

AnnieBrooke, pls let me ask  you this question. As had told you earlier, going by the November 17th date for conception, she should be delivering on or around 10th August 2015. And am now aware that if somebody delivers before the 37th week, it is considered a premature birth. Still going by November 17th as the conception date, the 37th week begins on 19th July. So my question is, if she delivers somewhere towards the end of June or in the first week of July, going by the scan, should I still be concerned by a DNA test? Thanks in advance.

[Aldior]

Thank you very much AnnieBrooke for your candid advice. I have already told her am ready for the DNA after the baby is born.

[AnnieBrooke]

Yes, probably.  If what the doctor said about the number of weeks is correct (and the due date does align with that), she would have had to have sex with someone between about October 1 and 10.  If that wasn't you, it would be someone else.  She might be protecting someone else, or protecting herself, by not admitting anything to you, she might also be a victim of someone that she is afraid of, so be careful here with what you say to her.  But in any case, do be consistent in offering that you stand ready to have a DNA test when the baby is born.  That will give you the answer you need.

[Aldior]

Do I have reason to suspect that it can be somebody different apart from me?

[Aldior]

That is on 16th August and 17th November. That's all.

[Aldior]

I mean we had sex on two accounts

[Aldior]

Thanks AnnieBrooke. Ok, We had not known each other for long. However, we had sex on 16th August. That's all. The due date given was 28 June 2015. On 11th January I tried to tell her we go for another scan, she refused. Though she insisted we can go for a dna after the baby is born to which I said I was ready. But after that she again goes back on her word and she says that she is ready to take care of her baby. I don't know what to think. Pls help.

[AnnieBrooke]

In other words, you could have gotten her pregnant in October if you were having sex with her then.

[AnnieBrooke]

What estimated due date did the doctor give her from the ultrasound on December 23?  Was the only time you had sex with your girlfriend November 17?  Were you having sex with her in early October?  The 13 weeks 2 days figure does not add up to her having her last period on October 20 or her getting pregnant on November 17.  But, if she was your girlfriend, i assume you didn't have sex only one time?  Had she been your girlfriend for long?