I am happy to tell you about the STBBIs (sexually transmitted and blood-borne infections) associated with penis-vagina intercourse and ways to reduce that risk.
The likelihood of transmitting sexually transmitted and blood-borne infections varies depending on: the type of sex you are having, the type of STBBI, and whether or not steps are taken to reduce the risk. Penis-vagina intercourse can involve risk to either partner for a number of common STBBIs. Chlamydia, gonorrhea, hepatitis B, herpes, HIV, HPV, and syphilis are commonly passed through penis-vagina sex, and though hepatitis C is also possible, it is less common.
Getting an STBBI test generally involves a sexual health assessment with the nurse or doctor who will ask you about your sexual or drug use practices and any activity that you think may have exposed you to an STBBI, like this situation. Being honest with them will help them advise you on which tests are appropriate for you, which will likely be screening for a combination of STBBIs (sexually transmitted and blood borne infections.) They may also be able to make a recommendation on how often you should consider building STBBI testing into your routine health practices.
Routine STBBI testing is one of the ways to reduce your risks. Why? Many STBBIs are treatable, meaning accessing treatment will help you clear it up before unknowingly passing it along. Also, having one STBBI can often make us more susceptible to infection from others. Completing treatment and clearing up infection keeps us and our partners safer in the long run.
Other effective ways to reduce the risk of STBBIs are: using condoms and water-based lubrication, engaging in other forms of sex that carry less risk like kissing, oral sex or manual sex (fingering and hand jobs), and engaging in conversation with our partners about routine STBBI testing.
I hope this answer is helpful for you. You may also like the Safer Sex Guide from CATIE.