Awesome man.  Both my sister and I are adopted.  Parents couldn't have a baby (3 miscarries, lots of depression).
Don't let anyone try to make you feel like you are not the child's real parents.  I consider to myself to have 1 mother and 1 father, the people I grew up with.  I am extremely lucky that the woman who gave birth to me chose to put me up for adoption though.
Best of luck 
