Should I Take Blood Thinners For Life Or Only During High-risk Events When Protein S Level Is Lower Than The Normal Range?

Hi Dr, I have a question I recently received my Coagulation blood test and found my Protein S to be deficient Based on the result, is it recommended to take blood thinners for life time or only during high risk events i.e Pregnancy / Surgery. Test result is 36 normal range is 55-124% according to lab result