My Coumadin Level When Tested Via Finger Stick Was 1.6

my Coumadin level when tested via finger stick was 1.6 vs what it should be 2.3 what happens when you put off weekly or bi monthly test and find out your levels are low as described here? I'M 75 YRS OLD HAD HEART SURGEY SINGLE BY PASS LEFT DESENDING ARTERY USING MAMMERY TO REPAIR BUT FAILED THEN USED 3 STENTS ATRIAL FIB 3-4 MI'S ETC. I'M 5'9. BUT I FEEL GOOD. I TAKE A LOT OF MEDICATION