Pregnancy or not

My friend has slipped two days of her pills because she thought it was her period week. She went to look for something in her purse and discovered that it in fact wasn't her period week. She said she has had unprotected sex and he came in her as well. She is married. But doesn't want to be pregnant. She's doing the doubling up on the birth control. She thinks she ovulated as well. Should she take a plan b