HI, I was treated for an sti about a year ago and symptoms did not persist but a few days ago I had sex with my boy friend (same sexual partner since the previous year neither of us have had any other sexual partners besides each other within that year) and since then i have had itching and slight redness on my inner labia with a faint welt or blister . I believe it occurred because we were fooling around without lubrication i think this may have cause chafing? I have experienced yeast infections and other irritations before and this doesn t seem to be the same. What are your thoughts?