Is beta of 5500 in week 4 bad?

Not Necessarily. Beta HCG should reach the 5000's in week six, or after 21 days after conception. Your dates may be incorrect. Check with your ob.
BHCG. B-hcg are generally useful in determining the status of a pregnancy. In a good pregnancy, they should double within 48-72 hours. If fetal heart rate was seen with an ultraound with a b-hcg of 5500 generally, it should be fine.