Looking for a job while pregnant - UK

So I am currently 4w+6, I am in the process of looking for a new job after being made redundancy in April. Bit tricky to find a job during this pandemic, but I’m really worried that I’m running out of time to find a job and still qualify for statuary maternity pay. I have a potential offer for an amazing job, and I’m just wondering when I should inform them that I’m pregnant, or should I just wait till I get it and I’m settled down? Any advice is welcome! Sorry if I posted this in the wrong group!