I told my boss when I was 8 weeks pregnant. I only told her then as I'd not long started working there and wasn't sure how she'd "react"and wanted as much time as possible to find a new job if I needed to iykwim? Anyway my boss was soooooooo excited and told me she was expecting me to tell her I was preg as dh and I had been married for sometime and her and I are same age and she had 3 kids lol. Funny how things work out.

Good luck with your pregnancy and telling your boss.