Contraception is not murder. It IS a grave sin, potentially mortal. Abortion I’ll grant you is murder, but not contraception.
Contraception ALWAYS functions in its primary role to prevent the sperm and egg from coming together. The pill tries to suppress ovulation, the IUD primary method is to create conditions toxic to sperm, the condom, diaphragm, etc serve as physical barriers to sperm reaching the egg (sometimes with spermicidal chemicals too).
Some contraceptives have secondary effects which can be abortifacient. These are arguable unintentional side effects, so you can’t really argue that when they occur they are murder. The primary purpose of cars is to transport people, but we all know that a small percentage of car users are killed by them or kill others in crashes. That isn’t murder for the same reason.
Put the pitchforks away, I’m not minimizing the seriousness of contraception. It is sinful in its own right. The sin just isn’t murder. Catholic teaching is not well served by well-intentioned, but poorly reasoned hyperbole.
The OP question should be phrased differently. If a medication is prescribed as a corrective medication for a non-reproductive medical issue, it isn’t contraception. Even if it is the “pill.” Personally, I think people would be well served to find less toxic alternative medications, but using a pill for acne or PCOS treatment is NOT contraceptive use by every legitimate catholic teaching authority I can find. Even those who are sexually active can use medication that has unintentional contraceptive side effects without sin.
It is the INTENT to engage in sex divorced from its procreative potential that is damaging to the soul. When,say, the pill is used for a legitimate medical purpose, the unintended side effect does not necessarily cause the same spiritual damage (i.e. sin). This is the same reason that people who have themselves sterilized, but then repent and confess this sin are not required by the Church to seek sterilization reversal.