Hello May,
My story is a little similar to yours. I have a 9 month old daughter, so I gave birth in April 08. While in the summer, about June/July, I started having back pain. I did get an epideral and so I honestly thought the back pain was from that. So, I decided to go to the doctor becuase I would wake-up in the middle of the night from dreams that my back was being stabbed. I also did have pain during the day, but mostly toward the end fo the day. So, I went to the doctor, she ordered a regular x-ray and everything was normal. Then I had an MRI. This was in October. During the MRI I denied the contrast since I would have to "pump and dump" for 48 hours. They told me if they found anything they would reschedule so I could store some milk. Well, before I left my next appointment was scheduled. I called my primary doctor and she said they had found a sryinx. Since they found the sryinx they went ahead and did a whole scan and found I had a Chiarri malformation. So, I did my other MRI with the contrast. Then I went to my doc so she can tell me exactly what Chiarri is, but of course I am her first patient ever to have it, but she did already schedule my appointment with a neourologist and a neourosurgeon. I have met with both of them already and have had some nerve tests done. My neourosurgeon did say the back pain isn't caused from the sryinx, I do have some bad disks (not quite sure if I believe that cause it never hurt before, but then being pregnant does a lot to your body). I did learn that you can have Chiarri without a syrinx. So, you should totally look into getting an MRI. My neorologist told me at my first appointment that the first visit he usually schedules an appointment with a neorusergeon. So, I hope that helps somewhat.
PS I am probably looking at surgery in May, but I am now on the quest to interview different neuorsurgeons cuase I am going to be very picky!