Would really like other input.

My husband and I have always said we were only going to have one baby. And in May of last year our son was born. I have the IUD but have heard stories of it moving/not working and people ending up with oopsie pregnancies. To prevent that as a possibility we decided together that my husband should get a vasectomy. Well as the dates for my husband’s snip and my son’s 1st birthday approach I keep questioning our decision to only have one. My husband swears up and down that he is done and does not want another baby. We have both said we don’t want one in 5 years because of the age we will be (currently both 27) and I definitely don’t want one right now. I really think I’m just feeling this way/second guessing because I’m sad about how my pregnancy/birth went but I’m not sure. The birth was pretty traumatic and soon I won’t have a little baby any more and really miss him being little. Is this the one year itch people talk about? Has anyone else experienced this? I just want to make sure I’m not crazy. How could you tell the difference between wanting another one and wishing you could redo your first pregnancy/birth/new born stage? I really think I’m just sad the getting pregnant/having a baby part of my life is already over and it went by before I even realized it.