I don't think you are being selfish at all you need to be 100% sure of your decision!!
I've just had a TL when I had my daughter who is now 2wks old. It added on an extra 5mins to the op!! I'm only 30 and my dh is 25 (yip another one with a toyboy

). I was offered it with my 3rd son who is 1yr but I said no then even though we thought he would be the last, then I ended up pregnant when he was 9wks old

. I am sure (have to be now anyway lol) that this is it for me!!
Good luck with your decision!!