An elevated PSA is scary. Unfortunately, there is a lot of waiting and down time with it. They'll do a lot of things to get you very alarmed and then schedule something for 5 weeks later.
BonzoDog, one of our other members, wrote a post a few months back that mentions some other things he might want to do and make sure he gets done - https://www.medhelp.org/posts/Prostate-Cancer/Prostate-cancer-recurrence-/show/3068149?sort_by=oldest
You might also want to look into some of these and talk them over with this doctor while you wait for the biopsy -
Research everything. Just start googling terms, like PSA or whatnot. You only get so much time with the doctor, and even the best doctors just can't tell you everything.
I know it's super scary right now. Whatever happens, whatever the results, remember that there is always hope. He's young, and you are on top of this. My dad was diagnosed with a very aggressive form of PC, and had a 15% 5-year survival rate. He was 70. He lived more than 12 years, and had other serious health issues that complicated things.
Keep us posted.