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If you have begun your period (or will start soon), you may have special worries about changing in the locker room. Your best strategy is to be prepared: make sure that you have pads, liners, and/or tampons on hand all the time in your gym bag or locker. If you are on your period, consider wearing dark underwear and/or pants and bottoms. If you're worried about wearing pads, especially in gym class where you are more active, you may want to become comfortable using tampons, which are much more discreet. Ask to see the school nurse if you feel cramps coming on or if you feel queasy. You can tell your teacher that you aren't feeling well (keep it somewhat vague). Then tell the nurse, of course, about your situation. Remember that you're not the only one going through this, and most girls are more than willing to help each other out when one of them runs out of supplies or begins her period unexpectedly. In fact, it's sometimes a way to bond! The male locker room has its own issues. Many guys are worried about how their equipment stacks up, and are concerned that others will be comparing them. If you're a guy, you may also be worried about having an unexpected erection at an inopportune time. You can try to prevent this from happening from keeping your thoughts as non-sexual as possible while changing. For example, think about the upcoming basketball game instead of the date you have planned for later this evening. It may also help to wear tighter-fitting underwear, such as briefs or boxer-briefs, instead of loose boxers. If you do have an erection, this can make it less noticeable. It never hurts to drape your lap with a towel when you are changing out of or into your pants, as well. If you are transgender, then you are most likely facing unique concerns. It's important that you know your rights and find advocates to support you. Among your most important rights is the right to feel safe, comfortable and non-threatened at school. In many states and school districts, this includes the right to change in the locker room where you are most comfortable changing (whether that is the room that matches the gender with which you identify or the one that correlates with the sex you were assigned at birth). Even if your state does not have specific legislation outlining rights for transgender people, you are protected by Title IX against gender discrimination. If you're unsure about where you can change, or if you are being bullied or harassed, it's very important that you seek help from a trusted adult: a parent, teacher, counselor, principal, etc. You shouldn't have to deal with bullies alone. It's really hard not to look around the locker room and notice the differences between your classmates and you. If you have body insecurities, it's especially difficult. Try to keep in mind that everyone else (or nearly everyone) also has their own body issues. While this won't automatically make you feel better about your own body, understanding this can help keep things in perspective. If you are struggling to come to terms with your own body or your anxiety about changing in front of others, do not hesitate to talk to someone, whether that is a parent, teacher or counselor. See also our helpful wiki on how to accept your body.

Summary:
Be prepared for menstruation issues. Know that erections happen. Know your rights as trans person. Try not to compare your body to others.