5w2d ultrasound help

I'm 5w2d according to last period, but I have a longer cycle usually and I usually ovulate around CD 18 instead of the typical CD 14, which makes me think I'm probably not quite as far along as my period says. Haven't had my official appointment yet. It's next Monday when I will be 6w1d. But I work in the hospital as an X-ray tech so my friend that is an ultrasound tech scanned me today and I'm a little scared because my sac looks so small and I don't see baby. But she acted as if it's no big deal, it's just too early.