Can herniated disc cause just numbness without pain?

Hi doctor,

I have a question about a herniated disc in my back (L5 - S1) magnetic resonance imaging (MRI) confirmed about a year ago. I went to physical therapy, the pain resolved, and I continue to do the exercises for 10 minutes every other day. No more pain though. The thing is even before the pain (years before) and still now after the pain is gone, I seem to have a slight numbness or I guess I would not call it a numbness but rather I have less feeling on the left scrotum and penis area in comparison to the right side. Maybe 25 % less. Could this be from the herniated disc? It was there years before the pain and is still there now after the pain from the herniated disc has resolved. I have also noticed other parts of my body have more sensation on the right side as opposed to the left. The more sensitive the area the more of a difference there is up to 25 %. Is that normal? Is it possible to have a herniated disc only cause slight numbness for years without any pain at all? Also it should be noted this sensation of lessened feeling on the left side compared to the right presented itself a few months after I had a varicolectomy on the left side. Maybe the incision caused a little nerve damage? I would hate to think that this lessened sensation was getting worse over time at such a slow rate that I did not notice it until it was too late. I do not think it is getting worse. Should I worry about this? Also, now that the pain is gone does that mean that the disc is back where it should be or did the exercises only get rid of the symptoms?