I'm 20 weeks with twins and have been contracting for the last two days?

I spoke with my doc, and while she was very sympathetic, told me that if i were to go into labor, they would not do anything to stop it because the babies are not viable yet. I am supposed to "remain calm ( as if) and not do anything remotely strenuous, and avoid stress in hopes that they will stop on their own". So, my question is: even though I am having regular, fairly powerful contractions, has anyone done this and gotten them to stop? How did you do it? I'm not on bed rest. I'm at work, because the doc said to go ahead and go.