No there is not a drug test. It's a urine test to measure protein, blood, etc. However, quite frankly it doesn't make a difference because you are going to have to disclose everytime you've used any sort of drug. This includes dates.
What's going to have to happen is you will have to disclose the dates in which you used drugs on your DoDMERB history form. The doctor will then have to comment on the use. If you used, something like marijuana 2 times freshman year and explain that it was a bad choice, etc. the doctor can write it off as a poor juvenille decision. Usually end of story. Not sure how this is going to work when you say that you used marijuana (I'm assuming?), a few days before your DoDMERB physical. The doctor will not be able to write it off as a juvenille decision. Atleast I'm assuming. This is just my two cents.
Contact Larry Mullen, regardless. See what he has to say.