Changing jobs within the same Company

Hi,

I work in a supermarket and found out in September I was being made redundant, cut to November I find out I’m pregnant so I have secured the same job at another store to make sure I get maternity pay. I’m not starting there until January and I’ll be 12 weeks pregnant by then, I haven’t told my new store & I don’t fancy turning up on the first day and telling them the news. When do you think would be the best time to tell my new manager? Or do you think I should bring it up with my current manager. Our store is closing down so will be completely new managers at the new store. I have worked for the company for 9 years.