Could just be a canker sore due to infection or food allergy (happens to me) or your molars shifting in. I doubt it's herpes, but idk what other stds inflict the mouth. You should go to your dentist if it persists. With herpes you're more likely to feel a tingling on your lips (like little bubbles are brewing under the skin surface) then shortly after there are multiple little fluid filled bubbles on your lip! It sucks but it's not too bad. Try gargling paroxide (which would also kill the virus).
The scabs are located by the back teeth and are painful. Kind of paranoid that this is herpes haha
I have oral hsv and never in my life have I had scabs on the roof of my mouth. Only when I try to eat really hot pizza.
Hsv is more prone to show up on the lips as opposed to the inside of the mouth (usually a canker sore).
I had a 3 year relationship with lots of oral involved, including when I had canker sores. To this day he is hsv1 and hsv2 negative.