I had exactly the same situation last pregnancy - was 3cm dialated from 30wks, on nefidipene patches 3x day til 36wks, 3min apart contractions for the whole last trimester, loss of plug, bedrest and 5 seperate hospital stays of 2 days or more for pre-term labour (from 20wks-36wks).............

Ds was kicked out at 37+6, by my choice! No sign of labour in sight either after all that.

So while you should act as if your life depends on keeping him in there via any means possible, you may very well still be kicking round at 38wks or later so dont panic and stress yourself.

Good luck, I really hope you make it to 36wks atleast!