Your results seem un-clear. It could mean 4 different things:
1. May be recovering from acute hepatitis B infection
2. May be distantly immune and test is not sensitive enough to detect low level of HBsAb (or anti-HBs) in serum
3. May be susceptible with a false positive HBcAb or anti-HBc
4. May be undetectable level of HBsAg present in the serum and the person is actually chronically infected
You may want to consider consulting a Hepatologist.
Please see the HepB welcome page for some info on pregnancy concerns and check back here for more replies. There are people here much more knowledgeable than I.
Welcome Page:
http://www.medhelp.org/health_pages/Hepatitis/HepB-Introduction--Welcome-Page/show/34?cid=153