THANKS FOR YOUR REPLYS :)
You can usually "see" the heartbeat by the 6th week or so, but you won't be able to "hear" it on a doppler until week 10 usually, or later.
by the 5th or 6th week, depending on the sensitivity of the ultrasound machine, whether it's a vaginal or abdominal ultrasound and, well, to be blunt, how "plump" you are
the heart starts beating at about 5.5 weeks.
I saw the baby and heartbeat at 6w4d on one of my pregnancies so around this time. Hope that helps