Oral sex carries no risk of hiv transmission, ulcers or no ulcers. There has not been a proven case that a person acquired Hiv by only having oral sex. The saliva in your would have inhibited the virus (if any).
Thank you for replying. Can I have unprotected oral sex with my partner?
Unprotected oral though, carries risk for other stds. Perhaps you would like to rule out the possibilities and to protect your loved one as well...