You certainly exhibit symptoms of a reherniation. I am glad your Dr ordered a new MRI (that's exactly what he should have done)
In all likelihood the report is right and perhaps you don't have a new herniation. As Carol said, you could also have scar tissue or inflamation. If the steroids settled things down, maybe inflamation is part of it.
I was told over and over by the surgeon who did my 1st Lami that, "Oh, it's just scar tissue" ....he didn't want to acknowledge that "perhaps" his Greatness had missed or overlooked something.
I had the same symptoms, my MRI was negative, my Dr totally disagreed w/the Radiologist' findings and subsequently it was discovered I had a massive reherniation (after Lami) at L5/S1.
This is NOT to say this is the same for you, it's quite possible that you do not have one.
What type pain are you having in your leg? is it the same as before surgery or is it more neuropathic in origin? The tingling hopefully is a good sign and could just be the nerves settling down.
Unsure when you had your surgery and how far post op you are?
Your Dr NEEDS to listen to you and if he doesn't - FIND SOMEONE WHO WILL.
Keep us posted
and Good Luck!