Hi Sandra,
Before a diagnosis is given to a patient, results of the various tests/scans are considered by an MDT (Multi Discipline Team). As regards timing, this largely depends on how many cases are awaiting determination and when an individual's case comes up. This means a diagnosis may take longer at some hospitals than others. The patient and a partner often find this wait stressful but don't consider a long or short wait means a bad or better result.
Many men who are diagnosed with PCa have no symptoms whatsoever and some men are found to have had PCa for years when they die of old age. So these men had no treatment. Then there are other men who have been diagnosed where it's believed that they are likely to benefit from treatment. If your husband was not experiencing extreme fatigue before he started having tests, it is likely that these tests, possibly causing concern and lack of sleep, may be responsible. PCa generally develops slowly over years.
You may be aware that if men live to an old age, most of them will have developed some Prostate Cancer, also that there are different types of PCa and individuals can respond to these very differently. For those who it is thought would benefit from treatment, should know that treatments have advanced greatly in recent years.
Difficult I know, but it means patiently awaiting results. Suggest you tell us diagnosis when given and as much histology as possible, so we can better understand your husband's case and make more meaningful responces should he be found to have PCa.