Please help advice needed

Hi, I’m 10 weeks pregnant and before I found out I was pregnant I smoked a lot of marijuana literally every single day. I live in a legal state and have my medical card but once I found out I was pregnant on May 18 I stopped it all together haven’t touched it since. I just got my drug test results back from a few days ago and tested positive for Marijuana and I am freaking out bc how am I testing positive when it’s been since May 17 that I smoked? My OB said that if I test positive one more time (next appointment is in 2 weeks) that they will then have to dismiss me from there practice. It’s the only practice in my area that takes my insurance. Anyone know how I could still be testing positive and what I can do to help clear my system? The only thing I can think of is my fiancé smokes occasionally maybe once a week but I always make him do it in the opposite room so I don’t have to smell it or be near it just to be on the safe side. I’m freaking out so any advice greatly appreciated thank you!