Typically, if everything is perfect (uterus is not tilted back, mom's pubic arch is lower, baby is in a good position in the uterus), I can hear baby around 10-11 weeks. There have been times, however, that I could not pick it up until 13 weeks or so.
Now, is that weeks in fetal age, or from LMP? I only ask b/c my mw said I was further along, she thought, b/c she could hear baby at fetal age 9w1d. My calculations could be off, I guess....
That's from LMP. I've heard it early - like around 9 weeks, but that was with an 8th time mom that has a very low pubic bone! It's pretty rare to hear it that early! <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/wink1.gif" style="border:0px solid;" title="wink1">