Blisters around genital area (picture attached)

Hello, im new to this forums so i'll try to do my best to explain my problem.

Im having this small blisters that become big in a matter of hours; They start as an itch, then a small blister appears, and then it starts growing and it actually hurts a lot, especially with jeans.

So yeah ... i had been tested for Herpes and Syphilis and got negative in both, so i have no idea what i have, so i will appreciate a little help on this matter.

I attached a picture of one blister which i hope dont grow any larger because it hurts badly.

Thanks-

See your doctor soon! They can take a quick sample and identify the blisters. Also medication to keep the fluid fro the blisters from spreading. Alwayways wash your hands . I hope it nothing serious! 

This may not be an STI, but those look like strange and seem to be growing very fast, so I'd see a doctor if I were you.  You could either see your GP, or if you're in the UK, you could go to a genitourinary medicine (GUM) clinic - google "GUM clinic near me" for details.

If you could update this thread and tell us what the doctors say, it would be appreciated.  Good luck.

Disclaimer: I'm not a doctor. 

See a skin doctor asap. It could be Scabies and if so they spread easily.