Congratulations, teasleromani123 
The most important thing is to stay off the fags.
Ideally you should also be cutting out nicotine however the risks from nicotine alone are not huge and NRT is routinely prescribed to PG women who cannot quit without it. This is from NHS choices -
Nicotine replacement therapy (NRT)
You can use NRT during pregnancy if it will help you stop smoking, and you're unable to so without it. It's not recommended that you take stop smoking tablets such as Champix or Zyban during pregnancy.
NRT contains only nicotine and none of the damaging chemicals found in cigarettes, so it is a much better option than continuing to smoke. It helps you by giving you nicotine when you would have had a cigarette.
You can be prescribed NRT during pregnancy by your GP or an NHS stop smoking advisor. Or you can buy it over the counter without a prescription from a pharmacy.
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When it comes to deciding whether to use an ecig, it's trickier because on the one hand they are not medically licenced (although they are regulated as a consumer product) while on the other hand they seem to work much better for lots of people than medicinal NRT products.
There is a growing pile of research around ecigs and none has so far found any evidence of harm or any mechanism that is likely to cause harm. There's a very good review of all the research to date here (the full paper is free to access but you need to create an account). It's true though that while we do know quite a lot about them, we don't know everything. We don't have any longitudinal studies yet or any on outcomes in pregnancy.
You don't need to worry about taking in too much nicotine. If you started to have too much, you would just feel a bit sick and put it down, the same as you would with a cigarette.
The idea to try a nicotine free one is actually a not bad suggestion. Some people find this is enough on its own, others find they do ok on nicotine free with just an occasional drag of low strength nicotine liquid.
Good luck!