I have trouble and I'm 22 weeks. I got all the way to the floor to clean up or pick things up.
I noticed I was having trouble somewhere around 24-26w, I think.
I'm having trouble now I'm 19 weeks +2 days but this is also my third so belly filled out really quickly ... I find it hard to bend down and clean up toys I have to go on my hands and knees to clean them up!