“我不后悔”和“我不后悔做了这事”用regret分别怎么说?

I don't regret
I don't regret doing it.
regret to do 对要做的事遗憾.(未做)
regret doing 对做过的事遗憾、后悔.(已做)
I regret to have to do this,but I have no choice.
我很遗憾必须这样去做,我实在没有办法.
I don't regret telling her what I thought.
我不为告诉她我的想法而后悔.