I made an appointment for birth control but want it for more

I made an appointment at planned parenthood (this was my first time) to get the paragard. However, this is all without parental consent and self pay. I’m 17 (18 in 5 months). My mom was never on board for getting me on birth control, she knows I’m not a virgin but doesn’t want me to have sex. She also doesn’t want to take me to the obgyn because overall, she’s ashamed that others will think she raised a hoe & that if I’m on birth control, I’ll be fucking anything that moves which isn’t true. I want to get std tested and on birth control but I don’t have a lot of money & since I only put it for birth control, can I ask to get tested that day and get it done? My parents can’t find out cause they’ll freak. I made the appointment for a day that I’ll be getting out of school early from. Any advice? And will I be able to get the iud that same day? I just can’t keep going back because this is probably the one of few chances I have to go and get it done. I had a pregnancy scare using condoms only and don’t want to conceive anytime soon.