Preterm labor???

I'm exactly 30 weeks and woke up in the middle of the night with severe lower abdominal cramping.  Waited til morning and it didn't subside.  Called OB and she said report to hospital.  Turns out I was having consistent contractions 2 min apart.  Gave me drugs to stop the contractions.  But my cervix is only dilated to 1 cm which they said is not enough to indicate labor, even though at 30 weeks it should be 0.  Did an ultrasound and baby is head down in my lower abdomen/pelvic region, but they didn't seem concerned since the drugs stopped the contractions.  I was discharged with orders for bed rest but meanwhile the lower abdominal pain is still quite bad.  Like something has definitely happened to cause this much pain but they weren't able to provide an exact diagnosis.  Just said it's not labor yet, go home and rest.  I'm a little frustrated because the pain is still there and persistent which I'm sure isn't normal.  They said come back if I'm bleeding or leaking fluid, which I'm not, but meanwhile I'm supposed to lay in bed with all this pain???  Yesterday I was taking work phone calls, cooking dinner, walking to the park, and now I can barely move.  Anyone have input on what's going on?  Similar experiences??