I Am Prescribed Hydrocodone For Pain And Had To Take

I am prescribed hydrocodone for pain and had to take a swab drug test due to an injury of no fault of mine, at work the injury occurred the day before, I took one of my 5/325ml @ 9 a.m. The next day and after getting treatment for my injury I took a swab drug test around 3p.m..... Because my medication is prescribed for me is there a chance I would be fired.....