Ready for baby number 2?

I will be 31 this year, my son will be 2 1/2 this month and we have been talking about baby number 2. I don’t want my kids too far apart in age or to be over 35 when I have another (not that I think that’s too old to have children, just my preference), it would be ideal to become pregnant soon...baby fever is definitely in the air, but I’m feeling torn between TTC and enjoying the stage my little boy is at right now. He’s just so fun and his little personality is growing and shining! I don’t want to feel like I missed out on a special stage with him because I was pregnant or occupied with a newborn. I know he’ll be a good big brother, but even though he’s a full on toddler I still think of him as my baby! I guess I just want some opinions from others who have been in this situation. How long did you wait before TTC baby number 2, what made you KNOW it was the right time?