I just got it today! And used on;) I'm real 12 weeks + 4 days and I am obese (ie with the belly) After finding the baby (it puts a bit of time), we hear very well her little heart :) We must press for against, so I do not know if it's due to my stomach where if the other women must rely as much as me. I recommend this doppler, it's magic! Go I return this time with the PC speakers.