An I-pill should only be used once in a period of 6 months,
If taken more then that, it could lead to her being infertile for the rest of her life, infertile as in not being able to have children due to the damage of consuming these I-pills like if they were candy.
I suggest you using protection as in condoms.
Also, ask your girlfriend if she is willing to take birth control pills.
I-pills contain mass amounts of hormones, etcetera, so therefore should honestly only be used 2 or 3 times in a lifetime.
Hope this helped.