Alternative smoking for pregnant women?

I have been smoking since I was 16 (wish I would have never started). I am now 5 months pregnant and have attempted to quit smoking 4 times already. The first day its all good. Second day I get jittery, cranky, headach, etc. All the symptoms of withdrawal. Its so hard. I heard about the e-cig and decided to try them. They actually wk. Just wondering if this is a safer alternative to smoking vs traditional cigs. I read that quiting smoking all together can stress my baby from my dr and several others. My mother smoked with me and my brother and we both turned out great! Thing is it still bothers me to smoke and quiting is so much harder than it sounds. What do you all think?