Baby 1 (once in place) by about 30ish weeks stayed in left side whole time. She really loved to stretch out and jam her feet up into my right ribs. That felt great!
Baby 2 was on the right side from about 32 weeks to 39 weeks. I was worried that this position would set me up for back labor. One night baby decided to make a move and flipped to the left side. 41+3 and baby is still on the left.
Fwiw I am really long waisted.