plan b please help.

yesterday i had unprotected sex and i was suppose to start my period today but sometimes i start later. i wanted to get plan b but my lover told me he didnt came at all and i had nothing to worry about. rn i just feel kinda bloated and i have light cramps and some discharges. but is it too late to buy plan b? yes i made a stupid mistake, i will use condoms and plan to take some form of birth control.