Hi there ~
I understand your concerns. I believe that you might be harming your baby if you continue to smoke marijuana and the baby may have to go through withdrawals anyways since you are so close to your delivery date. Informing the delivering physician about your usage is very important and I would also advise you to take care of yourself by quitting usage today and visiting with a psychiatrist
for symptomatic treatment of potential withdrawals from the drug.
I hope this helps. Take care of yourself and have a lovely day!