There could be several outcomes to your situation. No matter what, you should request the Doctor do an MRI or
CT. Sometimes waiting around for a doctor to make the call doesn't help your situation, especially when no one else knows your pain. I went to my primary care physician, a chiropractor/spinal manipulation, nerve specialist and the orothopaedic specialist before anyone gave me the right answers or sounded like they knew what they were talking about. If anything, go to a spine and neurosurgery center to get checked out, you might have to find out if you have to be referred, but don't ask your doctor, call the s&nsc yourself to get the right answer. When I went, the doctor questioned whether or not I had actually seen any doctors before him and was surprised at all their outcomes and comments about how it was either in my head or it wasn't a big deal, wasn't like I was going to be paralyzed from my back slipping off my spine.
So, don't listen to all those that question you, tell the doctor what you want and don't be afraid to speak up.
When I found out I had spondylolisthesis, I also found out that mine was congenital (had it at birth) and that the spine never fused. But it wasn't until I was pregnant for my last child (3rd) that my back began to have problems and my right leg (upper). Kept telling my pcp that something was wrong and she just kept getting short ended with me, ended with her talking badly to me. I just wanted help and answers for why the pain was so bad. After the baby was born, I requested they do more tests. I had a nerve test done to figure out if my trapped nerve in my groin (right leg problems) was from my back or trapped in the groin. Also requested they send me to the spine and neurosurgery center... the doctor said you should never wait to get answers when it comes to your back, because in my case he said there was no telling when my back would have slipped again and yes, it could have slipped off the spine and I would have more than likely been paralyzed. To think I was lifting the baby and car seat, as well as my 50 pound daughter in and out of a shopping cart at the grocery, little things like lifting groceries from the car to the house....
Your fall on the ice could totally be a whole new injury, but if ibuprofen or tylenol and a heating pad isn't helping or if it hasn't gone away, go get it checked. Let us know how it goes. Good Luck and God Bless.