I had the same pain in my tailbone several weeks ago. Went to my chiropractor for some adjustments and haven't been achy there since. I'm now 37 weeks :)
I'm having really bad lower back pain too...at times it feels like my tailbone is being ripped off.
Sometimes when I stand up from a seatied or squaring position the insides of my legs (groin to about 3in above my knees) cramp. I've also noticed numbness in my legs...at times, like they have fallen asleep :(
I don't understand it...
I'm just over 29weeks along... I have a little less than 10 weeks left.
Im going through the same thing as you. I was trying to explain to my husband that my tail bone hurts and also when I walk I can feel it going down into my legs. Im going to ask my ob tomarro and see what his suggestions are for relief