Marijuana and pregnancy.

Hi ladies, 
I am 19 and no where near planning to have a baby anytime soon. But in between now and When I do have one, I would just like to know about everyone's FACTS and knowledge that they have (not assumptions and not opinions) about marijuana, pregnancy and how they link together. 
So basically, I smoke the herb every now and again so does my SO. Me and him always talk about having kids, having a family in the not so distant future (maybe when I'm 25) or something because he will be already 30 by then. Now i am not okay with smoking while pregnant, drinking alcohol and all those things, I have made a conscious decision not to do ANY of that while pregnant. (P.s. I only smoke weed nothing else so it's easier for me).  But my question is, even though I'm not smoking while pregnant, the fact that I use to smoke will it take a toll on me still? How many months/years should I quit before to get it all out of my system to start the journey?
Thankyou in advance xx
Please no hate nor small minded comments ✌🏼️