Jaundice test was done after 7 days of birth of my baby with bilirubin level of 15, is there any concern about taking jaundice test so late(7 days).

Ok if baby is normal: Many normal babies between the ages of 4 and 14 days have a bilirubin level of 15. As long as the baby is normal (as assessed by one's pediatrician), that bilirubin level should not be a problem. For example, such a baby might have jaundice and a bilirubin lab test result of 8 at age 2 days, 12 at age 3 days, 16 at age 4 days, 18 at age 5 days, 15 at age 7 days, 10 at age 14 days, 5 at 21 days.