Question: what happens if you don't change your pad for 12 hours?
Answer: No matter how light your flow is, or even if there is no flow, bacteria can build up. Changing your pad every 3 or 4 hours (more if your period is heavy) is good hygiene and helps prevent bad odors. ... If you keep pads zipped up in a makeup case, no one will see them if things fall out of your backpack.