advice?

I have a question! I do not want to make anyone mad, I just would like some advice. I don't technically smoke, but I vape. up until I found out I was pregnant I was on 18ml which is how much nicotine is in it. I've dropped down to 12, this week I plan on dropping to 6, and then to 0 next week. do any of you know if vaping without nicotine is safe? I'm addicted to my vape, the nicotine was just for the nicotine high! I want whatever is best for my baby, so any input will help! I've though about making it where I only vape once an hour or something, just to cut back? i dont know! I need. opinions and advice! I don't have my first doctor visit until Oct 15th so I can't ask them until then! thank you guys