Preterm Labor 😞

So I was 28w5d and started having only mild contractions after sex. Thought it was just Braxton hicks! Well about 45 minutes later I figured I'd better start timing them because they kept happening. Sure enough they were 2 minutes apart so we called the doc and were told to go to L&D. When we showed up I had already dilated to a 1, and 2 hours later I was at 3 and 80% effaced. I got admitted immediately and put on a magnesium sulfate drip. I labored through the night and well into the next day- tears, yelling, the whole bit. But then my cervix stopped changing! I stayed in the hospital for 5 days until I was no longer in real pain. Got sent home on Procardia and strict bedrest. They couldn't find a reason for this to infection, sex shouldn't have caused it, and I wasn't stressed. Doc doesn't seem to think I'll make through 32 weeks. Anybody have this experience and carried to term? I'm 30w2d now.