Hello! Not exactly a menstrual cup question, but I saw the tag and decided to ask here.

I'm a 20 year old virgin, but I am in a committed relationship and will probably end up losing my virginity within the next year or so. I am already on the pill (to regulate my period) and we have easy access to condoms, but I'm an extremely paranoid and worrisome person so I want to add another contraceptive method just to ease my mind, so I thought that a diaphragm sounded like a pretty good idea, given that it could also make period sex a bit easier. I've been trying to do some research online before my first GYN appointment, but I haven't been able to find much and I still have many questions. So...

What can I expect for my first fitting?
I would prefer one made of latex. Will I be able to choose the material my diaphragm is made of without it affecting the cost too much?
Will using the diaphragm on my period decrease its effectiveness?

And if anyone could link me to a decent resource on diaphragms, that would be much appreciated. I can't find any!

Thanks! <3