Yolk sac

So I went today thinking j was going to find a heartbeat but apparently I ovulated a week late and I'm only showing 5w3d at most but he said they couldn't see a yok sac . Told me it could mean that things wouldn't be successful or that it could be to early or that it could be twins which makes it to where you can't see it. My gut tells me everything is okay. And I'm sticking with that. I go back next week to check on everything and get the verdict. Any body else have to deal with that?