I lost mine at 34 weeks and went all the way until 40 weeks.
I lost mine at 30 weeks. 45 minutes later my contractions started and were 5 minutes apart. They stayed that way for an hour so I went to L/D and they monitered me. I wasn't actually going into labor but my contractions were every 1-3 minutes. They have me medicine to stop the contractions and sent me home. I am now 36+1 and still having them... about every ten minutes now. I think it may just be different for everyone! And your mucus plug can "grow" back
I've been losing pieces of mine too since 1 week ago and im still waiting. With my first i lost it the night before with me second i didn't even see it and with this one just waiting.