Taking emergency contraceptive TWO times in a week is very unwise. It's for emergencies and if you are having that happen more than once a year? She needs to go on birth control immediately otherwise it is not using that medication responsibly. Emergency contraceptive is a big dose of hormones which is how it works to prevent pregnancy from happening. But then you have all those extra hormones circulating in your system which she has x 2 since she took it two times. She will likely have irregular bleeding and periods for 2 to 3 months. It also will be difficult to predict when she might ovulate again so you need to use condoms to make sure pregnancy didn't happen. The med she took works most of the time. Her symptoms sound like hormone overload (expected) rather than pregnancy (which that early on has little to no symptoms.
Get her on birth control! good luck
So, please read what I wrote and try to understand. HORMONES cause those symptoms and she just had a huge dose of hormones TWICE. That can cause what she is experiencing. But she can take a pregnancy test 2.5 weeks after the episode of unprotected sex (the last one to make sure). I expect it will be negative. Symptoms are not used to diagnose pregnancy early on because so many other things cause the same symptoms (even PMS and a period on its way). She is reacting to the hormones most likely that she took herself.
Sizzle, it is probably all from the morning-after pill, not from pregnancy. If she is still having symptoms, she could take a home pregnancy test, but it doesn't sound likely.