I don't know if I'm explaining this right 
I'm 39 weeks with dc3 and been feeling pressure for about 2 weeks now but mw said babies head still free (apparently engagement doesn't really happen in 2nd+ babies??
Just sat down and leaned forward slightly and felt a horrible and severe pain pushing right down into my pelvis and and basically right onto my lady bits
I had to bounce back and sort of recover it was really quite alarming. Any ideas what it was ?