I'm afraid I can't answer you with any confidence. Yes, these could be herpes, though they could certainly be something else as well. Has your boyfriend definitely been diagnosed with oral herpes?
I think that you need to overcome your embarrassment and see a doctor. That's the only way you're going to know for sure.
But because you got one blister and then another 2 days later, herpes is less likely than if you got a cluster of blisters at the same time. Also, the first attack of herpes usually produces severe pain and high fever. These are reassuring, but not conclusive. Please do yourself a favor and check it out.
Best.
Dr. Rockoff
Don't be embarrassed; your doctor sees this stuff all the time.
You could have genital (hsv-1) herpes from this exposure. If your blister dries up, I would recommend getting a HerpesSelect blood test ( you should ask for it by name) after 6 weeks and then at 12 weeks (if the first one comes up negative) to get a definitive answer.
Good luck!!
Thanks