Milk Of Magnesia

Have any of you ladies taken Milk of Magnesia for constipation? I took some Phillips MOM last week and it some what worked. I'm having severe problems going! I always have these problems but now that I'm pregnant it's much worse! If I'm lucky I can go once every week and a half to two weeks :( I've tried seeing 2 doctors for this but they told me to take Colace or Metamucil and some other stool softeners - but nothing works! Fruits and veggies don't even help! I drink tons of water also :/