do you have an early 6-8wk u/s? if you do, see if you can locate the yolk sac, it generally looks like a hollow circle with a white rim to it. use the location of that to determine in place of the placenta, because it may not be easy to spot. however, i've read that the placenta looks like a dense mass of white lines on the u/s which it all looks like dense white lines to me. I had a transvag u/s at 7 wks and i believe i spotted the yolk sac above my baby which is tucked all the way to the right (boy)