Avoiding the Creepy Check-up

An 18F, finishing up high school and still living with my mom (34F). So, a few months ago, my mom started dating this new guy who's 50. Okay, age gap weirdness aside, things got super awkward for me personally. About three months ago, my periods started getting super bad. Like, talking unusually heavy bleeding and major cramps and just a lot of pain that I've never dealt with before. Obviously, I was like, "Okay, time to see a gynecologist," because I haven't been to one since I was 15 and this isn't something to mess around with. Also it's time to get a routine pelvic exam anyway. I told my mom, thinking she'd be supportive and help me make an appointment. We live in a pretty remote rural area right now (my high school has literally like 50 students), and it's like an hour drive to the nearest urgent care even. Also the insurance I'm on sucks and I need her to help me with the co-pay. But nope! The next day, she's like, "Guess what? My boyfriend can do your check-up!" Yeah, turns out he USED to be a board-certified gynecologist, but got his license yanked away a few years back. And why does she want him to do it? To save money on the co-pay since our insurance kinda sucks, and to avoid driving two hours to see a doctor in town. Now, let me be clear-this guy gives me the major creeps. He's done stuff like not knocking before entering my room, making weird jokes that are definitely not okay, and just giving me those vibes that scream, "Stay away." So, the thought of him being all up in my business for a pelvic exam? Hell no. When I said as much to my mom, explaining there's no way I'm letting her boyfriend anywhere near me like that, she lost it. She said I was being insulting, assuming the worst about her BF, and that I had hurt his feelings by suggesting he couldn't be trusted. She said I was essentially implying he's a pervert. It ended with her saying I was grounded for even thinking he was some sort of creep. So, here I am, feeling stuck and kinda violated by the mere suggestion, and punished on top of that. Am I the asshole for standing my ground and not wanting her boyfriend to do the exam? so she runs to user's house her neighbor a 6ft 300lb muscular hell's angel.