Di,
Sorry you have someone going through this.
The rough sequence of events, if it eventually leads to a prostate cancer diagnosis is:
mpMRI scan of abdomen/prostate
Biopsy
Initial diagnosis given, but extent not always clear yet.
Nuclear Bone Scan (usually, but not always done)
Abdominal CT Scan (rarely done)
PET/CT Scan (rarely done)
Whole body MRI scan (rarely done)
Treatment options given.
Obviously, you bail out of the process any point up to the initial diagnosis if you are found not to have prostate cancer.
Each diagnostic procedure, analysis of the results, discussion by the clinical team, and you having a consultation to feed back took about 3 weeks in my case. They often go straight from the mpMRI scan to biopsy without an intervening appointment (particularly during COVID), which speeds thing up a bit. But you are probably looking at 4-6 weeks, plus any extra COVID delays.
Prostate cancer diagnosis is rarely very urgent as you may have heard with some other cancers. The cancer usually moves slowly.
We know this is an anxious time, being hit by something new you probably know little about, and not knowing where it's going to take you, and feeling like you've lost control of your lives. I'm afraid you just have to wait out this diagnosis period, supporting each other, and of course you can ask questions here, but we can't predict the results of the diagnosis. When you get to treatment choices, you will be starting to understand things better, and that marks the start of you taking back control.