The physical at OCS is not as involved as the physical you recieve at MEPS, just a once over. That's not the point though, showing up to OCS with an STD is bad ju ju. You will receive hygiene inspections at OCS, and your rash will be brought to attention at some point, which will ultimately resulting in you getting kicked out of OCS, and all the guys in your platoon remembering you as one of their favorite "guy who got kicked out of my platoon" stories for years to come. I recommend you go to the doctor as soon as possible (as in, stop reading this post and go now), and I also recommend minimal skank-railing from here on out.
By the way Doc- outstanding Simpson's reference in the signature.