Welcome to Healthcare Magic forum.
I believe you must have come across this term in the Ultrasound
Pouch of Douglas is a potential cavity in the women's body. This is the lowest space of the abdomen. So if there is any leakage from the structure inside the abdomen it has to final reach Pouch of Douglas.
So when the ultrasound report says minimal fluid in Pouch of Douglas it means that all the abdominal organs are intact. If there is excessive collection in the Pouch of Douglas that indicates abnormality.
If there is minimal or no fluid in the Pouch of Douglas there should be no problem for you to conceive.
Hope I have answered your question.