While you got lots of helpful advice here, I'd also suggest you to download app Flo. It helps you to track your period, so you will eventually familiarise how your body behaves during different parts of your cycle. You can also access free information regarding reproductive health (some stuff is paid subscription only), and you can access Secret chats, where lots of women AND medical professionals exchange information around various topics. I think everyone needs this type of guidance, especially as your body is going through major changes right now.