Need to vent / a little nervous

Let me start off by saying I have had one pregnancy this far, and it was a healthy one thank god so I've never experienced a loss of any kind and hope i don't ever..

But I have a doctors appointment Monday to see how far along I am and have my pregnancy confirmed by ultrasound (I should be 6 weeks by that time if I'm not already)

And even though this isn't my first pregnancy and I've already had a healthy one I'm a little nervous.

I keep thinking about what if I go and they tell me that it never developed a heart beat or that it stopped growing?

I know chances of a miscarriage are rare but not uncommon but I'm praying I never have to experience a loss. But I'm still nervous.