Hello, My Gf Took The Morning After Pill, 2 Weeks

hello, my gf took the morning after pill, 2 weeks later she saw her period on time. Her next period is now delayed for 2 weeks. We did not have sexual contact between the 1st period after the pill and the due date of the 2nd period. We had protected sex 5 days after the due date of the 2nd period. She's 2 weeks late now and having no signs of her period coming. She's been quite stressed during that time and we went on a trip a week after the due date and only had protected sex. Also, she was drinking water with lemon before the due date so that her next period would be shorter.
What are the chances that her period is just delayed this much?