Hi,
I am in a similar situation I have a 4 month old and think of starting ttc in Jan!
My GP told me, health wise it's advised not to ttc for 6 months after a baby so you'll be fine.
but make sure your body stocks up on vitamins and iron before u get pregnant coz it will be draining especially with another baby.
I personally am planning to start around Jan/Feb and from next month I will start to work out a little so I can shape up and get stronger for next pregnancy.
Good Luck I am excited for the thought of it.!