With my DD, I was doing shared care with my GP and the hospital where she was born. I went to my GP one day and he spent somewhere between 20-30 minutes looking for her heartbeat. He even walked over to the phone and picked up the pad with the forms for the local scan place... then he thought he would have one last try and finally found her... freaked me out. i reckon i would have been close to 20 weeks from memory...