Astro_Zombie

I've been going through the hiring process for GE for a while now. I've already taken a urine test and since they've let me keep going through the process I would assume everything turned out alright there, today I had class and a test and now tomorrow I have to go in for a pre employment physical. I've been told that they will be doing a blood test and a urine test. It's going to be on GE's grounds.
Since I've already taken one drug test and passed will they be testing my blood and urine for drugs? I haven't smoked since Sunday and he test is on Thursday. I mean, and I freaking out? Is the physical for medical reasons only since they've already made us take a drug test? Would they test both blood AND urine?
HELP HELP HELP!!!
I have the Physical tomorrow afternoon.