Hi there. Well, I have a sixth grader and a seventh grader. Lots of girls at your age (how old are you?) have their periods and any gym teacher would expect this. Learning to talk to your mom is very important. This is just the beginning of questions you'll have and moms expect it. She doesn't know what you are thinking and I'm sure would WANT to help you. She buys the tampons, right? So, if you have a question, she's the best one to ask. No one on the internet can really help you like she can. Take a deep breath and say "um mom, about school and swimming--- I need to come up with a plan when I have my period . . ." and go from there. Not weird at all or anything to be embarrassed about. good luck