My hcg level on 4th week was 277 and after 5 day it was 648.. is it normal?

Look for doubling: Not sure if the level is too low in general but we look for doubling of the HCG level every two to three days in early pregnancy. What's the progesterone level - should be monitored as well as it supports a healthy early pregnancy. With doubling, 277 should become 554 (or thereabouts) two to three days later, then 1108 two to three days after that.