Could My Girlfriend Be Pregnant If She Took 4–5 Emergency Pills In 3 Months, Had A Light Period Two Months Ago, Missed Her Period This Month?

My girl took 4 or 5 emergnecy pill in time period of 3 months. 2 months before she had light period for the first time. we did the test and it was negative. We did four times. and this month she didnot have period on time. We did test and it is negative but we are still not sure if she is pregnant or not?