Don't take risks! Those things are sometimes hard to control...? :)
My husband and I never had unprotected sex before we checked his vaccination results (some fail) overs 6 months after he started the vaccine (there are 3 doses over 6 months). It is just safe, reasonable and fair for both of you.
Good luck!
Go to the doctor's office and get hep b vaccination before you do anything. So you don't have to worry about anything. Also, good for your future too.