We struggled to conceive at first. We tried for over a year then consulted a fertility Dr. The reason we never got pregnant was because I have psoriatic arthritis and I had to be off my meds to try and conceive (and as a result was on a lot of pain). I was referred to a specialist that specializes in autoimmune diseases and pregnancy and he explained to me that your body will almost never conceive when you are in pain because it is the body's natural way to protect itself (natural selection). He got me on medication that was safe during pregnancy, I felt better and quickly got pregnant. Just thought I'd throw that out there as I know you have back issues.