12 week scan and telling work

[Islandermum]

I need some advice, I can't seem to come up with a solution to this.
Context: I started my new job yesterday and have been given my shadowing shifts for the next week. The shifts are 'early shift: 7.30am - 3pm' and 'late shift: 2.30 - 10pm'.

I have today received my 12 week scan in the post. For 8.40am on a day which I am doing an 'early shift'.

I called up the hospital, who have said there are no other slots either that week or the week after. I do not want to tell work that I am pregnant yet as this is a brand new job.

What should I do? I need my 12 week scan, but I also need to look reliable at my new workplace...

I would be inclined to apologise to work and say that you've been scheduled a hospital appointment that you must attend that day, and that as it is urgent you will need to attend. I'd then see if you could swap your shift - or offer to make up the time. Technically, they shouldn't ask what the appointment is for, but I would be as honest as you can at this point - I plan on doing the same, without actually revealing the reason for the appointment.