Thank you for your query.
Firstly, the I pill
commonly causes some amount of bleeding or spotting a few days after consumption.
So what your girlfriend experienced was pretty normal as far as I pill goes.
Also, the I pill is known for preponing or delaying the normal period by a week or sometimes 10 days also.
So that could be cause of absent periods in her case.
is not 100 % effective, so it could just as easily be an early pregnancy
If she does not get her normal period 4 weeks from the date of taking the I pill, please take a urine pregnancy test.