Update:
Well I found the heart beat again this morning, what a relief.
I have a doppler that I rented from Stork Radio (one of the more expensive ones out there),,,,,for weeks I was all excited b/c it was so easy to pick up the heartbeat..only to find out that I was (this was at 12 weeks) listening to my own artery.....If you're picking it up anywhere near your hipbones, and it's wicked loud....it's probably your artery.....In addtition, we all have an abdominal aorta that runs right through your abdominal region, which i wicked easy to pick up too........Since the midwife found the HB...I've never been able to find it on my own! UGH! And I'm 19 weeks, 3 days today! And the screen that gives you the supposed heart rate isn't accurate...All very frustrating, I know....I don't mean to discourage you at all...but just know that if you have a hard time finding it.......you're not alone! Try bringing it to your next appt. with you and see if they can help.
Yea, it's because at this point in the pregnancy the baby is so tiny. Normally doctors don't even try with a doppler til about 11-13weeks. :) don't worry about it. I STILL can't get my son's heartbeat w/my cheesey little doppler, and i'm 32weeks.