Pregnancy

I’m not fully sure if that’s what stopping me, because it can also be him but we’re both pretty young soon to be 20 and 21. I’ve been letting him release in me for a while now and there haven’t been a slight sign that i could be pregnant. In the beginning we were worried so i took plan B’s before. I’m not on birth control at all and all i do it smoke weed, I’ve seen people that smoke the same amount i do or more and still end up pregnant. I did some research and it said stop if ur planning to become pregnant and that it may lower the chances. This may sound odd but we’re not really planning I’m just a bit confused or concerned about my fertility.. i don’t know if it’s me, him, or the both of us.