Many are confused on the Church’s teaching of intrinsically evil acts. No circumstance or intention can justify an intrinsically evil act. Double effect doesn’t come into play with intrinsically evil acts. If we say that one can use contraception for medical purposes then we can say abortion is allowed to save the mother, which we know is false.
No. You are confusing direct actions vs. unintended side effects.
Let’s look at “abortion to save a mother’s life.”
If a pregnant mother is actively dying and needs to be saved, it will NOT be her child that is killing her. It will be something wrong with her own body that is killing her. Most likely, the doctor will treat her in order to save her life. Sometimes this requires a c-section (for example, the uterus is killing the mother). If the child is not yet viable, the c-section will have the unintended consequence of killing the child.
However, the doctor did not directly and deliberately kill the child.
In the case of using the pill for medical reasons, the reason for the pill is to cure a hormonal imbalance. That’s what the woman is directly using it for. The side effect is infertility.
NOW - with that said: if there is a drug that is known to have abortifacient side effects, it would be prudent for a Catholic woman to either (a) request a different pill, if possible; or (b) use NFP in addition to the medicine to avoid the chance of an abortifacient side effect.
Point is: the act in question is taking drugs. Taking drugs is a neutral. The reason for taking the drugs is where sin comes into play.
If you are taking drugs purposefully for recreation, to get high, as contraception, to commit suicide, etc: all gravely sinful.
However, if you are taking drugs to help you body, then it is not sinful.
Finally note two: It is possible for a women to desire to take the pill for BOTH medical & contraceptive reasons. In such a situation, I would imagine that having marital relations would most likely be sinful for her because the woman would not be open to life.
I pray this helps.
God Bless