I first got SPD after the birth of my first child, and it came back during subsequent pregnancies. The post birth pain after my first lasted around 5 or 6 weeks, getting better little by little. I couldn't stand for any length of time for the first month. I wish I had gone to see a chiro for some proper support as I was healing though as I suspect my 3rd and 4th pregnancies would have been much easier if I had. Hope you feel lots better soon xx