stupid question lol

my birth control says to take the first day of your period but I'm already on the 3rd day. its progestin only pills if i start it tomorrow is that okay and how long till it is effective? the pack says 48hours but I feel thats so soon lol and no I'm not breastfeeding .. my doctor told me everything about the pill except when to start it and its county clinic so its not like i can just call real quick for an answer........EDIT:I plan on using protection, I just didn't know when to start it. when I use to take combination pills it was the following Sunday after your period and this one is different lol