iphone 6 content has been wiped. Can I get it back

I got an iPhone 6 for Christmas. At the time I didn't have access to my lap top and just set the phone up as normal. I have just synced the phone with my laptop now and when I was setting it up I inadvertently clicked set up from previous back up. It has wiped all my content from my iPhone 6 and replaced it with things from my old 3GS. I'm guessing there is no way to get anything back?