MEPS Experience?

I’m going to MEPS next week for the Air Force and I was wondering what it was like from a female perspective, other than all the sitting around and waiting. My recruiter is briefing me on Friday for it, but he’s male and I’m worried he won’t be able to answer whatever female related questions I might have. If my period comes early would it be acceptable for me to use a period cup instead of tampon? I bleed through quick and don’t want to have to go to the bathroom every 2 hours to change it... Do I have to wear a normal bra or am I allowed to wear a sports bra if it isn’t a racer back?