First doctor's appt with no heart beat yet...

I had my first doctor's appt today and did the usual testing. During the US he wasn't able to pick up a heart beat. He told me it could be 1 of 2 things and that #1 I may have ovulated later than I predicted or #2 that I was having a miscarriage. He emphasized more that my cycle was probably off and I ovulated later and then scheduled me for another US in 2 weeks.
The first day of my LMP was 6/6/08 and which by dates would put me at about 8 weeks. He seems to think I am more like 6 weeks. I told him I had a positive pregnancy test 7/7/08 and he still thought I was near the 6-7 week mark. I am still having pregnancy signs and symptoms and have had no bleeding. The CRL for my 1st US was 0.64cm.
Has anyone else experienced something similar if not the same. I am really thinking I am not as far along as I initially thought too but I guess I won't know for a while.

Dont worry too much...with my first baby they didnt find the heartbeat till i was 12 weeks pregnant. I actually got one of those monitors u can listen to their heartbeat but it doesn't work till your alot further along.

They didnt check the heartbeat till week 12..thats about the time they do it b/c when i went to my first doc appt at week 6 she said my nxt appt week 12 we will be able to hear the heartbeat..its stll early for you

I wouldnt worry too much. I went to the dr at 10 weeks and they could not find the hearbeat either. I went back 2 weeks later and they found it. I thought I was miscarrying but I wasnt so Im sure everythings okay

I hope it is too early! I've heard that you can hear the heart beat as early as 5 weeks but hearing as long as 12 weeks definetly puts my mind at ease.

Quoting babiebump:“ I hope it is too early! I've heard that you can hear the heart beat as early as 5 weeks but hearing as long as 12 weeks definetly puts my mind at ease.”

i was 10 weeks when i went for my first appt and my midwife couldnt find the heartbeat... she wasnt even going to bother trying to find it but i asked to have a go. she warned me that even 10 weeks is very early to find the heartbeat as the uterus is still under the pelvic bone until 12-14 weeks.
please dont get disheartened yet.. give it a few more weeks  

Yeah, the doctor had to use the vaginal transducer because he couldn't pick anything up with the abd one. But after hearing that so many of you had to wait too it makes me feel so much better.
Now my concern is the CRL measurement. Mine was 0.64cm which by the CRL table I looked up I would be at 6.5 weeks which I don't know if that is all that possible.