Hi there. You haven't mentioned whether your cycles are regular or irregular and delayed. Either way now when you haven't got periods still,it's unsafe to have sex. If your cycles are regular then 5days just after periods and 5 days just before expected date of next periods you can have safe sex. But if you have irregular cycles this doesn't work. Now Once you finish periods the next 5 days you can have. For now I suggest you to take protection. No matter which day of cycle please use protection if you have no plans of getting pregnant as it surely prevents any std transfer and even you won't get pregnant.