Can someone help I haven't pooped a full movement in 3 days. I have so many hemroids and everytime I…

Can someone help I haven't pooped a full movement in 3 days. I have so many hemroids and everytime I try to go they flare up like crazy. Pregnant with my third child. I took milk of magnesium and it gave me the runs for like Iike 2 days. Then back to constipated. I would hate to have to take medication everyday just to poop. Someone know any suggestions