worried about telling work about pregnancy

[RiverSong]

I just feel do worried incase they start causing me problems in the four months ill be back. I know they ' shouldn't' but they might.

I feel awful talking to my manager when they say thing about long term plans. ( my maternity in no way affects them staff wise im a number in a centre)

How do i tell them? Is it best to wait until im back? Xx