Early scan?

Carys
Hi everyone,
I'm UK based and we don't usually get our first scan until 12 weeks unless we're high risk. This is my first baby and I'll be 4 weeks pregnant tomorrow. Thinking of booking an early scan privately for 7-8 weeks. Has anyone else had this done? And when would you say is best to have it? I want it late enough to hear the babies heart but early enough to reassure me that it's all good to be okay!