If you are having blood work done to specifically test your testosterone levels then yes it will affect your levels if you are taking it, but no "epi" will not show up specifically because they are not testing for that compound.
If this is just for a general health blood work, then no "epi" will not show up, but it most likely will affect other readings especially your "T" levels.
If this is for a drug test then the answer is still no. If they are testing specifically for steroids then they almost always start with testing your epitestosterone vs testosterone ratio. If these are out of normal ranges then they proceed to test for specific compounds. At this time it is when "epi" will show up.