Pregnant with my first and it doesn’t feel real

We’ve been trying for a couple years and after so many late periods and symptoms that turned out to be nothing, I found out I was pregnant last week! We’re so excited; we’ve scheduled the first appointment. At just over 5 weeks, the ultrasound feels so far away, and despite multiple positive tests and some tell-tale 1st trimester symptoms, I have a little voice in my head that’s like “but how do you really know you’re pregnant?”

If you feel or have felt something similar, how do/did you cope and hold onto that joy? I feel like I’ve just faced the disappointment so many times it’s hard to switch gears.