Only Child(ish)

My son is never going to experience what it's  like to grow up with a sibling. He is nine, since I am single. It looks like he will be into his teens before I have another child. If I have another child at all. I'm not sure why it hit me but I found myself writing a letter explaining this to him. I feel bad, Im sorry. I didn't intend for him to be an only child but I also didn't intend to have other children. I still can't say I'm sending a strong signal to the universe. I am at the "under these conditions" I could point in the journey. 

I know that he could still have a sibling but since the age gap is so large it would be different. I imagine it like having a cousin but I'm sure that's  a terrible analogy. I have a friend from Serbia who said that large gaps are common. Maybe so you can focus on one child at a time. Big age gaps mean totally different sets of demands.  Still I feel like I have deprived him of something. That will always be the case I guess.