"I have a feeling we might regret having this conversation."

I regret having to say this, but it's rather important.

But I'll regret having to make it to my dying day.

It's easy to make up and you'll never regret having one along.

"I regret having to tell a lady such a thing."

I regretted having this effect on women at the moment.

"Do you think she regretted having a private rather than a public career?"

He began to regret having to give up the case.

Of course I could never regret having my wonderful son.

He regrets having to use a car and travel by plane.