Can STD Be Contracted Through Unprotected Sex?

Hey there, 2 days ago I had a one night stand with a girl I ve known for quite some time. We had unprotected sex for around and hour or so, however I did not cum. Last night, I noticed that the glands of my penis under the foreskin had become slightly discoloured, sort of a brown/grey color. This morning I woke up and noticed that the glands had now become slightly wrinkled, accompanied with tiny white dots. There is no itching/burning/uncomfortable feeling when I am sitting around, nor when I pee. I know it typically it takes at minimum a week for std symptoms to appear, but I am not too sure what I could be dealing with. I m hoping that I m just being paranoid and just dealing with an infection of some sort. Any information would be greatly appreciated.