My fiancee is Catholic, and she knows that it can cause an abortion. However, her cycles are so irregular without it, that the pain cannot be controlled by simple pain medication and exercise. She also needs it to prevent ovarian cysts. Also, she might not even survive having a child (she has lots of medical problems).
However, she does not use it as birth control. We take other precautions, instead.
Taking BC pills for medical treat is one thing. There are a number of other treatments for cysts, and the problem with using hormonal medicine to regulate cycles is it can mask other major problems. My sister also had similar experience, and very nearly had to have a radical hysterectomy because the pills were hiding the real cause (can't remember the exact problem, I will have to find out).
Basically, be very careful trusting BC to "treat" anything. It is helpful in some ways, but it usually doesn't make anything go away or get better.
There are certainly other methods to treat these problems.
However, she does not use it as birth control. We take other precautions, instead.
Oh, wonderful. So she is on the pill, you are both unmarried and apparently having sex, and you are using other forms of birth control.
Three strikes and you are out in my book. Does your fiancee really consider herself Catholic? I sure don't, because for starters she is most likely under an automatic excommunication for procuring an abortion through use of the pill.