Drug test 2nd pregnancy

I've always smoked cannabis even during my first pregnancy. It doesn't effect my parenting abilities in any way. I never once got drug tested during my first pregnancy, I did have extra scans which I understood why. however yesterday I had an appointment I had never been to this side of the pregnancy unit before and they drug tested me to make sure it was only cannabis I was taking? My ex rang child protection last year to be petty as I broke up with him and reported I smoked cannabis. Bearing in mind my midwives, doctors, hospital workers and social worker I used to have due to my exes dv already knew I smoked. Could this drug test be because he rang child protection last year? I still have my child also if you're wondering there wasn't any concerns and I'm a brilliant mumma