Be careful if you want to be a doctor.
In principle, and even historically it's a revered profession based on serving those who can't help themselves. Good work.
But today, there's a good chance that you'll be put in situations that demand you to abandon Catholic morality. Sometimes the 'law' even demands it of you. And you could find yourself in a situation where you can keep your job and break God's law, or you can lose your job and possibly go to jail.
Obviously if put in the situation, the only right thing to do is to follow God. But I'm a firm believer in St Thomas More's thought, that we generally flee martyrdom unless there is no other choice. Opening my own business is a nice thought, but I'll never do it because I don't want to put myself in the very real situation down the road of having to refuse services to someone on moral grounds, get sued and have my family without a provider.
Of course, if one has a vocation to the single life, it's different. But I think in general, Catholics (men) who are called to the married life have a duty (within reason and with caveats) to not put themselves in situations where they're putting the health of their family at risk.
God bless