Rach, at that age, he can probably drink from a sippy cup also. That might be easier than teaching him to drink from a bottle and perhaps easier to watch also. Neither of my boys would drink from a bottle, but both were drinking from a sippy cup by about 4 months.

You might find that AF comes back once you start work. Mine came back at 7 months with DS1 (just before I went back to work actually), and at 6 months with DS2. It is so different from mum to mum - some get AF back as soon as their baby starts sleeping longer at night, and others go well over a year without her. GL!