Could a pill be made that instead of preventing pregnancy induces a successful pregnancy after sexual intercourse? This article seems to answer my question and is what inspired it, but I'm not 100% sure.
There are already hormonal treatments that increase ovules production in women: instead of 1 ovule per cycle, they induce the production of up to 20 ovules in a single cycle. Since likelyhood of pregnancy is proportional to the amount of available eggs, they do the trick.
It is important to note that a pregnancy with more than 1 embryo is something human body has not been selected for. The more the embryo, the higher the risks for both mother and embryo.
There are so many many factors required for pregnancy. Each one can stop it but everything has to be right for it to happen.
Imagine it as a chain. To stop it you just cut any link. To join the chain any link could be the problem.
No pill can fix everything that might stop it.
If the "pill" contained an already fertilized egg (zygote), then all it would have to do is get the egg to the right spot (nano-bots, or it's not a pill that's swallowed) and maybe have a few hormones to set the environment.
Intercourse isn't even required. As to who the egg's parents are...?