Final project idea

I started out by free writing so it might not make much sense

How would i improve the human body or even man kind as i know it.
-Unwanted pregnancies especially in teenagers is something ive always been interested in, in preventing.
-A birth control substance of a sort something that lets substance out (menstrual cycle), but lets nothing in (sperm) like a lock system
Something that gets inserted at birth and genetically grows with the body util the person is ready to have a child then they can get it removed surgically, but nothing painfull or with harsh recovery.
Something that covers the cervical opening like a type of cover with a screen or a tube.

Pros: this will prevent many many unwanted pregnancies
people will have children when they are ready to take care of a child
population control
Cons: will insurance companies cover it?
government approved?
is it moral?
should it be a choice
would it be available to all or just hospital births
Does not prevent STD and STI's

So this would not be improving the human body but it would inhibiting it of a feature
but this inhibition would help with population control, better the population,
decrease neglect of children, crack babies, orphanages, poverty, and many other things that I'm not thinking about