Brother in law moving in?

My husband received a text message from his 21 year old younger brother asking if he could move across the country and into our house. My husband then brought this up to me and asked my opinion. I told him I wanted to know why his brother felt the need to move in with us, my husband did not have an answer. I called my brother in law to get answers. It was like pulling teeth, but got him to admit that he had been fighting with his father and ever since their other brother passed away this past April he has been having a hard time adjusting. I told him if he were to live with us there would be ground rules that he would be expected to follow. Either he has to go back to school or work, he needs to save money for a place of his own, etc... I am very hesitant as my husband and I let another brother of his move in with us 6 years ago and that did not end well. There were a lot of fights between my husband and myself over it as well as us and his brother. On top of it all now I am 13 weeks pregnant with our first child. I feel as though this is just too much for me to take on all at once, but at the same time I have always had an open door policy... especially for family. My husband wants his brother to move in so we can help him out, just under the circumstances I don't know how much I have to give... Anyone have any advice?