Job Offer - Civil Service 38 weeks pregnant

[isitspringyet23]

I am 38 weeks pregnant and currently on maternity leave.
I do not want to return to my current job which are paying me SMP only.
I have been applying for jobs within the civil service for quite some time now , wanting to gain interview experience and hoping to land something with the understanding recruitment / onboarding can take months.
Last week I was offered a job! Interview was over teams so they do not know I am pregnant. I'm now worried as things do seem to be moving relatively quickly. I have a call this week to discuss pay and the working hours I have requested but I don't know when or how to disclose pregnancy/ current maternity leave and my requirement to start after.

For ref - there would be all the pre employment checks / dbs and bpss checks to complete too I don't know how long this would take I've read it can take 3-6 months but now I'm worried, it will be quicker. I would intend to return to work after the end of my 9 months statutory paid leave. Second and final mat leave - I would not consider returning earlier .
AIBU to accept and tell them im currently on Mat leave and my intended start date?

Please no pile on ... I'm aware I may have to chalk this up to experience and let this one go as I don't want to mess people around but I do really want the job but not at the expense of things being horrible for me when I finally join.

It’s the civil service, it will be fine. Just let them know asap

And congratulations

Usually public sector are fine to wait. I've known of people deciding to take a two month holiday before they start a new job.

You have no need to apologise or feel bad as you've done nothing wrong. Indeed, if they were to withdraw the offer, it would be actionable pregnancy discrimination, and I don't think the civil service will do that. You were under no obligation to tell them until this point, but obviously you do need to tell them now to sort out the admin. Congratulations!

I joined the civil service at 20 weeks pregnant. I didn't tell them until shortly before my start date. The response was absolutely fine. I asked the (older, male, childless) manager for a meeting in advance of starting and when I said I was pregnant he smiled and said he had thought that might be what I wanted to talk to him about, and then congratulated me and was entirely warm, friendly and lovely about it. He helped me with options re: start date and other arrangements and nobody ever made the slightest negative murmurings about me starting pregnant.
It will be absolutely fine.