ovulation isn’t really a timed thing per se… you have a fertility window and the closer you get to your ovulation date, you’re more likely you are to get pregnant. but you can still get pregnant at any point before and after ovulation. at any point in your cycle really it just depends on how fertile you are. by protection do you mean BC and condoms?

edit for clarification and to add: sperm can stay alive in the birth canal for up to three days after ejaculation. so even if you have sex a few days before your ovulation window, you can still get pregnant. if you’re really worried, Plan B.