We had protected sex again, about a week later, also using a condom and this time I was trying to go behind her (doggie style) and she was facedown on the bed meaning her butt wasn't up in the air.  I heard a pop and the condom broke.  I was not sure if I was inside her or not. She said I wasn't.  I believe I had a healing HSV-2 lesion on my penis near where the condom broke.  I wasn't sure if I was exposed to any vaginal fluids or not.  

I have been tested for HIV, Hep C, Syphilis, Gonorrhea and Chlamydia and all were negative.  What are my risks for Hep B?  How high or low is my risk for Hep B? Should I be tested this far out? This happened about a year ago now.

Hepatitis B virus (HBV) is sexually transmissible but rarely sexually transmitted between males and females in industrialized countries; sexual transmission is primarily a problem in men who have sex with other men. Active, transmissible HBV is extremely rare in even the most sexually active women, so it is very unlikely your partner had it. And if she did, the odds of tranmission from a single episode of unprotected vaginal sex is probalby under 1 in a thousand. With a condom, a hundred fold lower than that. Blood contact with intact skin isn't risky at all. Could an active genital herpes lesion elevate the risk? Perhaps, but still the chance would be exceedingly small.

That said, I have trouble understanding why you were testred for hepatitis C but not B. Even at the low risks just cited, HCV risks are even lower. In fact, contrary to popular beliefs (including the beliefs of many physicians) HCV isn't transmitted at all in heterosexual couples. (The frequency of HCV in the sex partners of infected persons is no higher than in the general population.) HCV is only sexually transmitted among MSM, and even then almost entirely among HIV positive MSM.

Finally, are you sure you haven't been vaccinated against HBV? If so, you're definitely not at risk regardless of the exposure.

Bottom line:  You are at no measurable risk of HBV from the exposures described. But of course you're always free to be tested if the negative result would increase your confidence about it.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

Last night I had unprotected vaginal sex with a female friend I’ve known. It was only about 5 minutes. I have HSV-2 but didn’t see any lesions on my penis and I’m on valtrex. She is also on an IUD to prevent pregnancy. 

She was tested for all STDs around May of this year which were negative.  She was also in a year long monogamous relationship with a male that ended in September. I believe she’s spent the past couple months healing and not sleeping around. Although she may have had a partner since then. But I’m just guessing. 

I was tested for everything back in November and was negative. 

What are my chances of getting HIV? Or her getting pregnant?

The main STD risk here obviously is your partner's risk for HSV2. Your lack of symptoms doesn't mean you can't transmit it to her. You need to tell her of your infection and advise her to be on the lookout for genital herpes symptoms.

She does know of my herpes status and was ok with it. 

Should I worry about this incident? I am quite nervous about it even though she’s a friend of mine 

I'm glad to hear you were up front with her about your genital herpes. Good show!

That completes the two follow-up exchanges included with each question and so ends this thread. I hope it has been helpful.