Dreaming?

Does anyone know why for the past couple weeks I've been having dreams of my ex boyfriend/ father of my child. We've been arguing for the past couple weeks and he said he's done but he's still going to be in the baby's life of course. 
Last night I had two dreams about him and we were happy and kissing and I woke up crying my eyes out. I really miss him but why have I been having these dreams about him, and us. 
I'm 39+4