4 long/short years

My baby could be turning 4 today.  That just breaks my heart.  I want to badly to be able to hold him and just be with him.  I know that just isn't what was meant to be but I still struggle with it.  Did I do something so wrong that karma took away my ability to have kids?  I just hate to think that my kid could be trailing around behind me, learning things about the world and soaking in the love I know he would get.  I sometimes feel like its hard to miss something that you never really had but those thoughts were there, the life was there and the love was there.  I had my whole world planned and suddenly that ended.  How can I go on to have more children when I feel like that is the wrong thing to do?  How can I tell the difference between my gut feeling telling me what is right for me and my guilt chastising me for what has happened?
I look at my husband and wonder what kind of life we would make.  Who would our child be?  I think often about the quirks and personalities in my family and wonder which of those things my child could have, what combination of traits would he posses?  My brothers and I could not be more different from one another but the things that make us up are inherently from our parents and families.  I see so many people in my face and mannerisms, what would my baby be like?  Holding JBU's 10 day old BU shows me the personality that a child can already have.  I want to know what that is like.  I want to create another person with my husband and watch him grow up and turn into someone.  I want to know what it feels like to carry my child and feel him move and grow.  I want to know those things with all of my heart.  But... I know that just may not be what happens for me.  I may not get those experiences.  I might not ever be that person I thought I would be.  I am learning how to be pretty happy with anyone else I am though.  I am starting to feel like maybe I can do this.  Maybe I can get through it all.