Some people have some naseous reactions while on the pill- when I was on a certain pill I would be nauseous quite often, and throw up if I ate bad things. It could just be that the pill is making you more sensitive than usual.
I switched pills and the nausea went away- perhaps you could switch too?
You could also try taking your pill at a different time, like at night instead of in the morning. Some people have had success with that, too.