pre eclampsia after birth?

So I had my son a month ago today, and ever since I came home from the hospital I've been experiencing terrible migraines. I had an epidural in the hospital so I've been thinking maybe I'm having spinal headaches because they are the worst pain ever. But when I called my OBGYN today to see if she could get me in and decide if I need a blood patch done she said she is going to test my urine for protein and check my BP levels also to make sure it's not pre eclampsia....has anyone had this?? I didn't even know this was possible