Hi there KG:

I too had this when DD was 35 weeks. she had engaged and her head banging against my poor cervix would send my body into raptures of pain and BH. i think it is your body relaxing and getting ready for her. DD was born at 38+2 weeks...
the feeling 'foggy' part i can totally relate to as well. i put it down to the fact that your mind is trying to disengage from everything other than yourself and bubs (again to prepare). i can just say to be careful when driving LOL! i accidently backed into a gum tree at 36 weeks as i was totally vague!!

good luck!