Hi, My question is that I want to know when I conceived? I don't remember my last period I know it's either the 18 of Oct of last yr. Or either the 25th of Oct of last yr. The problem is I had sex with a guy on the first of November with an condom on then a week after I had sex with another guy with no condom on. My ultrasound says I'm 20 weeks and 5 days pregnant based off my last ultrasound which was on the 19th of this month. Please tell me u can help me with this.

Date of conception is an inexact science and all based on Best Guess on given evidence.
As there is an issue with paternity then a DNA test will be required after the birth.

Even though the due date is Aug 1st. And when I count back 38 weeks it gives me Nov 1st . Is that the day I conceived or is that one week of when my cycle started?

Gestational dating is based on a mathematical equation using your LMP. There is no way to determine paternity by using this equation. You will have to wait until the baby is born to have a DNA test done.

Even though the due date is Aug 1st. And when I count back 38 weeks it gives me Nov 1st . Is that the day I conceived or is that one week of when my cycle started?

Yes, even then. How many women do you know who gave birth on their exact due date. The fact is that, as both your answers have told you, calculating due dates or conception dates is GUESSWORK! It is an educated guess based on a few different factors, but its still a guess. Generally, then can vary 2 weeks in either direction or more.

The only way to know, positively, the paternity of a child without a DNA test is to have had only one sexual partner since before your last period. Since that is not the case in your situation, you will just have to wait and have a DNA test done after the child is born. This means, that you should notify both potential fathers.

Sorry, but those are the facts.

Sorry, it is all estimated guesses. Due dates also.

At best, you can guess date you conceived by give or take one week. Often two weeks.
There is no way, anyone can determine an exact date of conception within one week.

You will just have to wait, and get a DNA test once the baby is born.

So is it true when they say your most accurate duedate is when your under 12 weeks?

I know you want to be able to determine who the father is, but you can't! Again, even the most accurate determination is still a guess that can be off by a couple of weeks.

I'm sorry you are in this predicament, but you are simply going to have to wait until this baby is born to be tested.

So is it true when they say your most accurate duedate is when your under 12 weeks?

Very early ultrasounds will be the most accurate, but they can not be exact. Usually, being off a week or two with a due date is not a concern, as there are several weeks at the end of pregnancy inwhich giving birth would be perfectly normal. With the situation of two possible fathers, it makes a tremendous difference, however. If your dates of being with the two men had been a few weeks apart, it would be a different story, but being only a week apart is too close, even with early ultrasound.

Ok. Thankx guys. I get the point.

U think u can tell by a 4d HD ultrasound?

No, you can't tell by a 4D ultrasound because an ultrasound dose not use DNA. You will only be able to see the baby clearer with a 4D.

No, you wouldn't be able to tell gestation with in a week even with 4d ultrasound. In fact, later in pregnancy, ultrasounds become less reliable for dating purposes. All you can really do is have DNA testing done after baby has been born, as was said. I know it must not be a very comfortable situation, letting the two men know the situation, but if you want to know for certain who the father is, you have no other choice.