CIGGARETTES OR VAPE?

My first pregnancy I couldn’t quit smoking until 7 months yes I know bad. Well this pregnancy I instantly put the cigarettes down. It’s been a week an a half. But I started smoking a vape and have dropped nicotine down to six mg. I asked my doctor if the vape was any better and she said not really... but if I got vape fluid with no nicotine in it can someone tell me if that’s still going to cause problems for the baby.. cause if so I wanna quit the vape all together.