Marijuana use post pregnancy

I haven't smoked weed in over a year and i took one hit today. So soon as I took it i felt overwhelmed with guilt and worry and stress im 2 weeks postpartum from a c-section and have my second appointment to check my stitches for infection Monday at the health clinic. They take urine at every appointment and this completely slipped my mind I've never asked if they test it for substances because I haven't done anything in so long and I'm so scared they'll try and take my baby. Please no judgement or rude comments i know i was stupid. Do they drug test or do you think I'll be okay? I'm going to try and push the appointment back.