I ve been on coumadin for blood clots after surgery for 16 months. I usually check at 1.4 to 1.8, once in awhile 1.0-2.6, and about 3 times 4.6 and 5.8. My doctor checks me often, lately, I m check daily. I have some large, some small very inky black areas come on my body and it takes about 3 weeks for them to fade. They are not bruise spots. I figure it has something to do with my blood. Yesterday my blood was 4.6, today 3.5.