A pregnancy can occur at any time during your menstrual cycle. There are times in your cycle when it may be less likely to become pregnant, but these times are hard to predict, especially if your periods are not regular. It can take many months of tracking to become familiar with your menstrual cycle. Use a regular method of birth control to prevent pregnancy. Where you are in your menstrual cycle doesn’t affect how likely you are to get an STI.
Use a condom every time you have sex (anal, oral, vaginal) to reduce the risk of pregnancy, STIs and HIV. Dual method use (using a male or vaginal condom along with another method of birth control like the pill, patch, ring or IUD) provides the best protection from pregnancy and STIs.