I don’t think there is a fair solution to this problem. The proposed contract You wrote is very problematic and not realistic.
What I think might be better, is more education around birth control, but also partners agreeing before having sex.

When I became sexually active, I told my partner that if our birth control failed, I would be getting an abortion and asked him his thoughts. I made it clear that part of consenting to sexual intercourse was us being on the same page of an accident happened. He agreed and we used our chosen birth control and it worked great, we never got pregnant.
Now, I know things often change when someone gets pregnant. However, I think agreeing on what to do if an accident happens should be part of consent, and talked about before sex. As in, if I am pregnant I will be getting an abortion or I will not be, if you choose to have sex with me, you are also agreeing to my plan.
I think of this is not talked about, the male involved needs to realize, and accept that he is consenting to the female doing anything she wants with his sperm and potential child-including child support payments for 18 years. It’s simply part of the responsibility required when having sex.
Once you put something inside of another person, it is part of their body and you don’t get to decide what happens with it. Before becoming sexually actively, individuals should be aware of what they would do if they got pregnant, and make sure their partners are on the same page as them, otherwise, don’t have sex with that person.