Congratulations on your commitment to safe, condom protected sex. You are at no risk from the theoretical exposure you might have experienced by putting your mouth on a condom that might have been contaminated by his genital secretions because you touched his genitals earlier in the encounter. The micro organisms that cause STDs do not survive well outside of the body or on dry surfaces. The sort of contact you had has never lead to STD transmission and I am confident that you will not be the first. Similarly, you cannot get an STD by touching yourself hours after a sexual encounter. The organisms would not have survived on your hand. You have nothing to worry about from the exposure you describe and do not need testing.
In addition, statistically it is unlikely your partner had an STD of any sort.
As far as your soreness is concerned, it is most likely due to the trauma of "grinding", not an STD. It will get better on its own.
Hope this helps. Take care. EWH
Actualy my private area is very sore now because of the grinding so despite the fact that I could have an Std is it possible that I could have injured my private area by grinding?