5 week sonogram any advice

I have a sonogram this week to determine better how far along I am more specifically just cause I have always had irregular periods.. I should be close to 6 weeks by Thursday, like 5 weeks and 4 days ish. I know their won’t be much too see, but I’m so nervous is this normal? I am so nervous I am going to get there and they will say there’s nothing there... I am a first time mom and a worrier 😭