Transvaginal ultrasound.

So after I had my first blood test done it was a little lower then my doctor like. I had my blood test done again and this was the results (10 day difference from the first one). My doctors office called today and said instead of my annual checkup with my OBGYN I’m going for a transvaginal ultrasound, so yes I have a 14 month old but I only had an abdominal ultrasound done with her. This is my first ever transvaginal ultrasound in my life! 🤣 I’ll be 6 weeks and either 1 or 2 days. Are they painful and what should I be looking at?