Relax. The risk of STD transmission is too low to measure. HIV and other STDs don't survive outside the body, even when kept moist. But even if contaminated with HIV or other STDs, exposure by skin contact--even with irritated skin--is very low risk. I don't recommend HIV testing. But if you remain nervous, check with your local health department and see what they have to say. In any case, if you get tested at all, you need to wait several weeks; there is no point in testing tomorrow.
Good luck-- HHH, MD
Good luck and don't stress.....