I second what Heather said. I had NO issues during my pregnancy (except for some bleeding around 12 weeks that resolved itsself, thank goodness). Had no lower packpain and hardly any swelling anywhere - just grew boobs! No braxton hicks to speak of - but never 'dropped' when I was supposed to -it felt like I carried my daughter up in my lungs the whole time!
She was also sunny side up and wanted NOTHING to do with being born (jammed her hand on my pelvic bone requiring a c-section after 24 hours of labor, so my time was up and I had a c-section). However, I started labor with back labor - don't even recall EVER feeling any contractions in my belly - all across the small of my back. This was NOT the case for my mom, so I'm not even sure it's genetic.
I will say that counter pressure was the only thing that helped - my husband just pressed really hard on my back during each contraction (until I had the epidural).
I wouldn't worry too much about back labor - I don't think it's too common, I am the only one I know of who has had back labor (well, except now I know of Heather who replied before me!)
Good Luck :-)