In Western countries and in Asia, fertility rates are pretty (edit: low) these days. I fear they would collapse with the introduction of a male fertility pill. In some sense, maybe that's not bad. The world is probably overpopulated. But if fertility drops too fast it creates real demographics problems in that few young people need to support many old people.
We should do everything to stop any unwanted pregnancies, and then add incentives and aid for everybody who wants to have kids (e.g. parental leave, free daycare, and so on).