I don't know if I broke mine but I definitly bruised it with my 2nd. I had a small baby 6lbs 11oz at exactly 40weeks. The placenta was right up against my tailbone, I had bad back labour because of it and it didn't go away until the placenta was born. It took a few weeks before I could sit without it hurting which is why I think I just bruised it and it didn't break.