Damn well dont let them know your problem until after you hit your "70 Working days" and then go see a doctor.... but Note: You wont be paid for time off are the days needed off to see a doctor or whatever it is the doctor says you cannot do for example "Dealing with Idiots"
and make sure you let your Union Rep know of your Medical Issue or Problem that is occuring once passed Probation.
Also keep track of your "Days Worked" bcus Managment will try to push you around for as long as possible hoping you dont know you passed probation yet.
Check in with HR to get a confirmation that you've passed probation. Even HR can act funny sometimes, I swear their all in the "Loop".