Not always. Many birth control pills cause the uterous to form a hostile environment and won't allow a fertilized egg to attach. Certain IUD devices do the same thing.
Contraception is not always about denying a willing sperm meeting a willing egg. It's about denying a fertileized egg a place to nest and continue development.
If pro lifers were honest, any Roe decision would also affect Griswold.
There are arguments made by some religions and cultures that any form of contraception is morally wrong. It doesn't even have to be after conception. The Catholic Church, for example, is against condoms.
At the other extreme, there have been cultures that practiced infanticide -- such as Sparta and, more recently, in China (girls).
The line has been drawn from before conception to after a live birth. This question has been with Man probably since the beginning. Even if Roe is overturned, it will not end the debate -- or the struggle over what the Law should say in this matter.
How about a more secular argument? Life begins at conception. As soon as the egg is fertilized, the only distinction between that embryo and the man on his deathbed is time.
But, the woman has a right to control her own body. It is merely an act of nature that this embryo has come to exist within her body. If I see someone laying on the side of the road bleeding, I have no legal obligation to stop and help, much less to offer my own blood transfusions, or organs, or lodging.
However, if I pick up someone lying on the road, drive them halfway to the hospital, and then decide it's too much bother and throw them back out on the street, I am legally liable.
So, the woman has no obligation to allow the embryo to implant in her body. The woman has the right to take any steps she wishes to prevent that implantation -- like driving by the drunk on the side of the road and NOT helping.
But, once she has accepted the implantation, she has accepted the obligation to care for that embryo, at least until it can be cared for by someone else (which for now means until it is viable). That her body may do so involuntarily is just another of those unfortunate truths of nature. The woman has the ability to stop it, if she doesn't she's stuck.
OK, I know we could argue that forever -- I just present it as a way to describe a rational secular pro-life position while allowing contreceptives that act both before and after conception.