ultrasound question

Hi ladies,
I have my first ultrasound at 7 weeks but they only do over the belly ultrasound (not transvaginal). Has anyone had a regular ultrasound at 7 weeks and was able to see/hear heartbeat? I'm worried because if they don't see anything, I'm going to have anxiety waiting for my next one so I'm wondering if I should just reschedule it to 8 weeks. What are your thoughts?