They typically say 2-4 weeks. But that's an average.
Check with your MD if you're feeling signs of labor though because just because you've dropped doesn't necessarily mean the baby is coming.
They said my first would not go to term. He was engaged and dropped, so low it was uncomfortable, for a good couple of months, but he was two weeks late and had to be induced 😂
I can't remember the exact week, but it was over a month for me. Everyone, including myself, thought I would deliver early, but my daughter was 6 days late technically lol