Maybe I'm reading too far into this

I am a 28 year old and for the last 5 or so years I have watched a good majority of family and friends get married and start a family. It's my life long dream to have a husband and kids because I never had the mother, father and child relationship. 
I've brought this up to my boyfriend and he always changes the subject or he says be patient. I'm not the one to throw out ultimatums all willy nilly but I am becoming impatient. 
What does one do in this situation?