Awww, sweetie.
It's a good idea to have a gyno visit before you become sexually active, to check for any abnormalities and find out what a normal, healthy you is like.
I don't know any woman that likes gyno visits, but they're so important to your reproductive health (not just for checking for STDs).
I've been tons of times (and when you're pregnant, you get your business messed with A LOT).
Here's what to expect:
Your doctor should get to know you and take your history while you are fully clothed. If you have any questions or concerns, let her know. If you feel uncomfortable or anxious, let her know about that, too.
She will ask you to change into a gown (or cover yourself in a sturdy sheet), and she will leave the room.
She will give you plenty of time, and then she will knock on the door to make sure you're covered up and ready for her. She will likely bring a nurse in with her to oversee and to protect herself and you from any sorts of allegations about misconduct.
Generally, she will begin with a breast exam. She should talk you through everything she does, telling you before she does it and explaining why she is doing what she is doing.
She will press your breasts with her fingers and move from around your armpit and the outer edges of your breasts in toward your nipples.
When she is finished with your breast exam, she'll allow you to cover up your top portion (you will never be fully exposed during the exam) and ask you to scoot down so that your bottom is resting on the edge of the exam table.
She will have stirrups out, and you will put your heels into them. At this point, you are fully covered (the sheet will be hanging down past your "business"), with your legs bent and spread apart.
She will have all her equipment nearby and will likely place a light near your vagina. When both you and she are ready, she will pull the cloth up just enough so that she can have access to your vagina, but not enough that you feel exposed.
She will be wearing gloves and will likely use a lubricant to make you more comfortable.
You will probably have a pap smear, testing for STDs, and a pelvic exam.
She will check your external genitalia for problems, and will use something like a q-tip (but it's not) to swab your cervix. This may be uncomfortable, but it is very quick, and very important.
One of the least comfortable things she will do is the pelvic exam. She will insert two gloved fingers into your vagina and simultaneously press down firmly on your stomach. The purpose of this is to check your internal reproductive organs.
This is also very brief, and she will be gentle and let you know exactly what she's doing.
When she is finished with your exam, she will leave the room and allow you to dress yourself before she comes back, or she may tell you that you are finished and you may leave once you are dressed.
The time actually spent with the doctor doing the tests and exams is very short, less than 30 minutes, if that.
So, just know this:
You are doing something very important for your health. Not only will you be checked for STDs but also for cancer and other things that might damage your reproductive organs and make it difficult or impossible to have a baby.
Your doctor will be very gentle, discreet, and she will help calm you by talking you through the process.
The exam is very quick and will be over before you know it.
Your body will never be completely exposed.
Many gynos have a calming photograph on the ceiling that you can focus on during your exam, but in case yours doesn't try to think of something that soothes you or makes you happy and focus on that to distract yourself during your exam.
Good luck...I know you can do this!
(Oh, and I think bringing your Mama is a great idea)