Tubal ligation

So obviously from the title I am wanting to get my tubes tied after I have my son. Idk if this is a stupid question, but how do I go about talking to my OBGYN about it? I have my 36 week appointment this Friday, do I ask for her opinions on me getting one? Do I just tell her that I have decided I want one? Do I even ask how she feels about it? I just don’t know how to go about bringing it up. I know a lot of places will try to talk younger women out of one, but I have my mind made up. This pregnancy has been extremely hard on my body, and my husband and I are perfectly happy with the three boys we have.

On another note, does anyone have any experiences they’d like to share with having a tubal done? Thanks!