Im 5 weeks 6 days pregnant I want to know when I conceived? Only because I need to find out who will father my baby.. I had slept with my ex beginning of march and another guy on march 20 so I need to know when I conceived... being with my ex for 6½ years and never got pregnantfofor 6¹½

Impossible to tell.
Gestational dating is all Best Guess.
As there is a paternity doubt the only surefire method would be a DNA test after the birth.

Was just told I conceived on march 16 by dr so still don't know what to think

The doctor doesn't know the exact day... they give you their estimate... in this case, his estimate was March 16.

As you were told, the ONLY way to be sure is to have a DNA test done.

Evem if they measured baby's size..

This is really going nowhere fast, isn't it...

There is NO way for them to know the EXACT date that you conceived.

DNA TESTING is the ONLY way you will know for sure who the father is.

Size has nothing to do with paternity. DNA does. You will have to have a DNA test after the baby is born.

Thank you

Ann, this is my job, my profession. I can promise you without a shadow of a doubt that there is no way to determine paternity without a DNA test.

Now you have to discuss possible paternity with both men. Since you are in a 6 year relationship I don't see this being easy for you.