I did a few weeks ago, and it sucked. Baby was just sitting really high and growing, so my rib cage needed to expand. Bra extenders really helped (all of my bras got too tight practically overnight), as well as going bra-less at night for a week or so. But basically, it was excruciating, and it felt like my ribcage was splitting open. But it only lasted maybe 10 days.
Could very well be the baby sticking whatever body part near there and putting pressure on it. Honestly with DD towards the end we were fighting over who got what space in my body, lol. I would dig my fingers where it hurt and I would feel her pull back outta there!