I'm glad you reached out and that you're taking care of yourself by taking PrEP. The first thing I would do is ask the provider that prescribed you PrEP (We are not medical professionals) but I can say oral sex has a small chance of transmitting HIV (it's considered lower risk) - this article tells you more https://h-i-v.net/myths-misconceptions but I'll paste it below as well. - Liz (Team Member)
Myth: You can’t get HIV from oral sex.
Fact: Oral sex, also called fellatio, blowjob, giving head (when involving the penis), cunnilingus, eating out (when involving the vagina), anilingus, or rimming (when involving the anus), involves using the mouth to stimulate a partner’s genitals. Although low, there is a small risk of transmitting HIV during this act. The risk increases when sores are present in the mouth or on the genitals of one of the partners, blood (including menstrual blood) is present, when a male partner ejaculates into their partner’s mouth, or when another STI is present. Brushing your teeth before oral sex does not prevent the spread of HIV. Brushing or flossing before oral sex may actually cause bleeding or irritation, which could increase the risk of virus transmission. Chewing gum or using mouthwash before oral sex may be better options if desired.4,15,16