It's a bit late for that - notification should have been done in advance.So, do I just call them up now and get them to come round and check it?
The position you're now in is that you've done controlled work without Building Regulations approval, and you have no completion certificate.
You may be able to make an application for "regularisation" - check your council's Building Control website for details. The fees will probably be higher than if you'd notified up front.