Sex on the last and first days of birth control pill pack with no condom

Patient: My girlfriend and I had sex when she was on her last pill of her pack, I did not ejaculate in her and I was not wearing a condom. The next day (2 days ago), on the first pill of her pill pack and the day after her period ended, I again was wearing no condom but I ejaculated inside of her. What are the chances that she could be pregnant? Also, would you recommend her taking any form of Plan B at this point if there is a chance she is pregnant?