herpes?

Hi all ,
           i had been visiting the sex workers here in india.
         i was worried abt hiv so i got tw hiv test done at 3 months and 5 and 1/2 months later which came back negative.

but yesterday i had burning in my scrotum area and today i see a blister there.  is it herpes? its been 5 ad 1/2 months since my last protected sex with  protitute.
How likely could it be herpes .I have one blister whihc is red .
How dangerous it is if it is herpes .I m very depressed plz help me out .
Should i test again for hiv?

[gracefromHHP]

You've covered the hiv base. go be seen today if possible to have your blister looked at and get tested for herpes if the provider you see thinks it looks like herpes.

grace