Is there a history of delayed puberty in your family? Have you talked to anyone in your family about this? Your lack of body hair seems a little concerning...that is another symptom of delayed puberty.
I mean, delayed puberty is a thing you want to get checked it. Sometimes, it's even a symptom of a larger problem. Did doctors ever express concern when you were 13-17 that you weren't developing at pace?
Either way, you need to see a doctor. I understand you may be a bit embarrassed, but just think of what they've probably seen throughout the day. It's okay to feel a bit silly, but just thank god you don't have to try and explain why you have a lightbulb in your bum. Make another appointment, and maybe request a male doctor if you feel a female doctor would hinder your ability to have a full exam.