Iphone 6S not connecting with laptop itunes

I'm trying to load music onto my phone from my laptop and when I plug the phone into the computer it says to download the newest version of itunes. When I check for updates in itunes it says its the up to date version. Should I try re-downloading itunes? I'm worried if I try a lot of music will be lost since it all off cds and I don't want to have to reload +70 cds into my laptop.