For the last 4 days I have had a sore blister on my outer labia. I did try to squeeze it a little bit, but nothing happened, I put some warm washcloth, but nothing happened. It just showed up just like that. Could it be herpes?
Yes, it could be herpes, but not necessarily. Your blister could have been caused by some of the systemic illnesses or allergic reactions, but it could be also irritated by your clothing, or a chemical burn or rubbing. It would be good if you visited a gynecologist immediately, as it has been more than four days now, the delay always makes things harder to diagnose. Good luck!