False labor at 32 weeks? I'll try this again...?

I am 32 weeks and last night something weird happened. I woke up to some intense contractions (12:42am). I have been having braxton hicks for a couple of months now, but these were different, stronger, the pain was crampy and i could feel them in my back and the tops of my thighs, so I started timing. By the time I got the 7th in 1 hour--roughly 5-6 minutes apart I called my doctor who told me to go to the hospital. I had to wait about 20 minutes for my hubby to get home (works night shift) and then we went. They put me in a room and monitored the contractions which continued at about 6 minutes apart for two hours and were getting stronger. At around 6am this morning they decided to give me terbutaline(?) and when she went to call the doctor to see if it was still safe (i have a heart problem) The contractions just mysteriously stopped. They monitored me for one more hour before I was discharged at 7am this morning. Has this happened to anyone? They were so regular for hours...