“I have a positive discogram?”

I had a discogram performed. The day I was treated I was experiencing chronic right lumbar pain. While on the table the first disc injected with a solution was l5-s1. I felt pain and tingling shoot down my buttocks, thigh, leg to my foot. Dr. speaking to another Dr. said "that ones positive" second injection of l4-l5 he said was "positive" l3-l4 injection no pain it just blew up like a balloon and I just felt pressure he said that one was negative. I terminated had debilitating chronic low back pain since 2008. Disc hernation at l4-l5 and l5-s1 and left leg nerve pain. Why did my Dr. say during my follow-up appointment my discogram was negative and that they no longer recommend fusion of the degenerated discs but want to implant a stimulator instead? How does that help with the instability? How will that get me standing straight again?