Pls am due for my period today 13th sept 2015 but is not yet out. i had an unprotected sex on 8/9 sept 2015. pls suggest pills to prevent pregnacy?

4 days out...: First, unless a woman is trying to have a baby, she must not have sex without a reliable form of contraception. Secondly, if she has sex, she should take an emergency contraceptive pill right away. It's known as a "morning-after" pill, but really should be a "minute-after" pill. At 4-days out, she can call her doctor now for an Ella (ulipristal acetate) pill; or ask about an IUD to prevent this and future pregnancies.