It can be tricky to tell the difference between a diaphragm and a cervical cap because they both work with spermicide and cover your cervix to prevent pregnancy. However, cervical caps are smaller and shaped differently than diaphragms. Diaphragms are shaped like a bowl, and cervical caps look like a sailor’s hat.
You can leave the cervical cap in for up to 2 days, but the diaphragm shouldn’t be in your vagina longer than 24 hours. Talk with your nurse or doctor to decide which one is better for you.