20 weeks irritable uterus

I'm 20 weeks 4 days pregnant with twins and I've been told that I have an "irritable uterus". I had to receive a shot of Terbutaline to stop minor contractions a few weeks ago and I've been able to deal with the "spasms" at home with rest and lots of fluids. Has anyone else had to deal with this? Any advice on how to deal without being down for a whole day? The pains take a lot out of me and I'm exhausted by the time they settle.