Currently pregnant

So I went to the er today they did an ultrasound and I was told they didn’t see a gestation sac but according to my last period I should be about 5 weeks tomorrow actually. And I am bleeding out of nowhere now should I be worried , he dr said it’s either I’m really early and he doesn’t think I’m miscarrying or having an ectopic but idk like they couldn’t even tell me how far along I am so now I’m scared cause I should technically be 5weeks tomorrow based off the last period I had