Unsure about risk and test results.

[Hereforfun3141]

Hi. I love what you guys do here. It really brings home what the internet is supposed to be all about. Creating a world wide community of people who help each other.

I am a generaly hetro guy with a curious side. I have been in a comitted relationship for a number of years but about 9 weeks ago i had an encounter with a guy.

During this encounter he masturbated himself and then me. Some precum of his precum was on my penis. He then rubbed his penis around my anus but did not put it in. There was precum all over my anus. He then fingered me for a while and we stopped.
A couple of days later i felt some stinging around my anus when showering. 5 days after the encounter i had sex with my partner. 6 days after the encounter i began to have flu symptons and what appeared to be a herpes outbreak on my anus.
My partner complained of a stinging sensation a few days later so i began to panic that i had given her herpes as well.
Things got worse 3 weeks after the encounter. I began to experience worse flu symptons, burning sensation when urinating and a very uncomfortable inflamed prostate. The doctor gave me some antibiotocs. I had some anal discharge on one ocasion. It was a clear fluid. So i persume i had a chlaymida/ghonerra infection. I took an STI test at 28 days from the encounter. All test came back negative. Including the hepBag test. 
Im unsure of what kinda risk this encounter was. But it does appear that i did pick up either chlaymida or ghonerra which i see is also described as unlikely from this event. The sti test did not swob my anus so would not have detected this. Its now 9 weeks since the encounter. My questions are:
1. Is it possible that i picked up Hep B from this event?
2. How accurate is my test result at 28 days?

[Lynn K]

I would ask your doctor to clarify your test results

“How is hepatitis B spread?
The hepatitis B virus is spread when blood, semen, or other body fluid infected with the hepatitis B virus enters the body of a person who is not infected. People can become infected with the virus from:

Birth (spread from an infected mother to her baby during birth)
Sex with an infected partner
Sharing needles, syringes, or drug preparation equipment
Sharing items such as toothbrushes, razors or medical equipment such as a glucose monitor with an infected person
Direct contact with the blood or open sores of an infected person
Exposure to blood from needlesticks or other sharp instruments of an infected person
Hepatitis B virus is not spread through food or water, sharing eating utensils, breastfeeding, hugging, kissing, hand holding, coughing, or sneezing.”

https://www.cdc.gov/hepatitis/hbv/bfaq.htm#bFAQc03