How long since you dropped?

I'm 31 weeks & sometime last week I dropped. I can see the difference in pictures & also when I used to sit down I could rest my boobs on my stomach(lol tmi) but that no longer happens. I get the sharp & painful pains of her head hitting off my cervix. How long after you dropped did you go into labor? I think I lost a small portion of my mucus plug yesterday too..?