6months pregnant, have trouble sleeping especially when baby kicking @ night. Can't take sleeping pills, can I smoke marijuana as a natural remedy?

Not recommended. The active ingredients in marijuana cross into the fetus blood supply and can affect neural development. Talk to your OB about alternatives that are safer.
MJ is naturally bad. Just because its a plant doesn't mean it's good for you. Many plants are poisonous. Weed harms the developing fetus. Increases the likelihood of prematurity. Increases chromosomal damage. Increases likelihood of learning problems later in childhood. Bad idea.
NO. You can not take sleeping pills nor should you smoke anything while you are pregnant.