What is this

I got noticed a bump last night on my outer lip and it was white at the time I popped it and now today it is like a blister but very tiny and does not hurt or isn’t causing me any pain. I do not know how to post a picture. 

Use a laptop to post it

This is what it looks like, does not hurt or anything. Got tested in january for everything and it was negative.

That is kinda hard to tell. I kinda looks like a pimple but it also looks like an ingrown hair. 

I’d go back to the doctors and get tested for herpes. Have them do a swab test. The tricky thing about herpes is that it can go dormant for a long while. So when testing it won’t show up. That’s why the swab test is a better indicator.