I'm on my period and missed 3' lo loestrin pills since my last pack ended 4days ago and had unprotected sex, how many should i take for ec?

Go to a pharmacy: If you want EC, you can get it over the counter at any pharmacy/drug store. It's much better than taking multiple birth control pills b/c it will have fewer side effects. If you want to use birth control pills as EC, you're going to need to take 5 pills at once, but I would only do this if you are UNABLE to make it to a pharmacy or your doctor. Go ASAP.