Preterm labor again

Brittanny
So I went to the hospital tonight and had to get a shot to stop my contractions. This is thee second time this pregnancy although last time I was admitted. They did a fFN test and said I'll get the results tomorrow but if it comes back positive I'll have to start procardia orally. Anyone ever take this and if so how long did it delay labor? Just from what I googled it sounds like it only holds it off by a few days?