Smoked and im pregnant

Yesterday I had some round ligament pain. And I smoked some weed. Heard from others that it doesn't effect the baby. And known some women who have smoked and baby has come out okay. My pain had went away and I was feeling okay. After I had stop smoking I felt something in my belly I thought maybe it was the baby but I'm 13 weeks and its my first It can't be possible. Then I had some nausea and I felt the round ligament pains again. My nauseas been really bad lately these past weeks. And this morning I had it again. Woke up okay no pain or anything. But thought about it and even though I don't feel sick or pain maybe I shouldn't smoke again.