I was wondering if anybody had fluid in their uterus and an enlarged uterus after giving birth? I…

I was wondering if anybody had fluid in their uterus and an enlarged uterus after giving birth? I just gave birth to my son two weeks ago and I'm in a lot of pain and I went for an ultrasound yesterday and they said that I have fluid in my uterus. And if you did have it what did they do to treat it?