My Husband Has PSA Levels Hovering Around 18. He Recently

My husband has PSA levels hovering around 18. He recently had a biopsy which came back non cancerous. He is complaining of intense pain (he never complains) located on his left side. It started in his lower back area and has now radiated to his left lower front and sometimes groin area. He has been taking amoxicillin (500 mg 3x per day starting this morning). He took another antibiotic after his biopsy for three days. He also received a shot prior to the procedure to make sure he didn’t have an infection since he has had a complete shoulder surgery. He doesn’t seem to have any other symptoms like nausea or sharp pains. He has passed lots of blood due to the prostrate biopsy which seems normal based on what we know. What do you think might be going on? My husband will call the Dr. on Mon., but I am wondering if he should be seen before then. He is not one to see a Dr. right off.