Isn't it bc of the relaxin? Mine have been cracking too, my knees are especially loud and I take more than the recommended dose of vitamins B, C, and Folic acid along w my prenatal and my dr said I was doing great nutrition wise. It's probably since our ligaments are loosening up already, I know my back has already started up.
No cracking.... but lots if body pain.....
Sometimes I hear some cracking in my back when I get up... I get up very very slowly as my back hurts and I get dizzy :(