Hi Fields! Smoking weeds or any kind of smoking is not a risk factor or helping factor to result in pregnancy that I can vouchsafe, Anyway had you had any unprotected sexual intercourse with your partener recently! If answer is Yes then for a recent exposure you did right thing to test urine for pregnancy but...... If answer is Yes but few monthsremote upto nine months then also get USG Abdoman for pregnancy. A baby s movements in uterus are known as Quickening and are felt fairly late in pregnancy about 4th to 5th month of the pregnancy. In that case every pregnancy test is positive. So you are certainly not pregnant but surely smoking bears bad effects on the fetus, So decide to quit smoking and make youself safe today and your coming generations for the future. Take Care!