Baby Measuring Small

Wendy
Went in today for my first scan at 8 weeks. Baby was measuring only 5 weeks and 5 days, with no visible heartbeat yet. I'm 100% sure of my dates, so I'm pretty discouraged. The doctor said not to give up yet, that he's seen this before where things turned out ok. I go back for another scan in a week, but I'm not feeling much hope at all.