How long does it stay in baby's system

I stopped smoking when i got pregnant. I'm a medical marijuana patients but I smoked a couple of times when I was 6 months pregnant to help with some pain I was having but then stopped. I'm freaking out it will still be in the baby's system when I have her. I know they drug test babies in my state. Anyone know how long it last. I know its only 30 days in our system but is it longer in a fetus/baby??