Um, abortion is NOT a contraceptive.
Some “contraception” can wind up being abortion.
The pill does not always prevent fertilization, but may prevent an embryo from implanting to the uterine wall. That is an abortion.
Plan B “may” do the same thing - depending on whether or not ovulation has already occured (Plan B is supposed to suppress ovulation, but it obviously cannot if the egg has been released prior to taking the prescription)
Ru486 is a chemical abortion.
IUD’s can also prevent living embryos from implanting - which is also abortive.