Low risk so don't worry. But avoid these practices. Transmission depends on viral load of the infected person. I have seen cases of non-transmission even after regular sex since the infected person has low viral load. I feel, infected person having viral load exceeding 20000 iu/ml (HBV DNA TEST) has high chances of transmitting during regular sex.
From Hepatitis B foundation blog website
http://www.hepb.org/blog/ :
"Oral sex doesn’t transmit hepatitis B. True or False?
True, but it’s complicated. There are no confirmed reports of hepatitis B infection resulting from oral sex, but there’s still a risk for infection. If you have a high viral load (HBV DNA), you may still be putting partners at risk of infection if they have bleeding gums, mouth sores, or anything that increases the likelihood of infectious fluids entering their bodies. Bottom line, oral sex has a lower risk of spreading hepatitis B than other sexual practices, but some risk remains. And don’t forget, other sexually-transmitted infections such as chlamydia, gonorrhea and syphilis are spread through oral sex. Using a condom or dental dam reduces infection risk."
Hope this helps.