my daughter ,a fit and active 21 year old has recently had blod clots in her lungs after taken the pill for just 6 weeks.it has been found out she has the factor 5 leiden and was told in hospital she would be on warfain for 6 months ,is it safe for her to come of this and how will we know for sure ,how do they tell when they take them off the warfain,?please help.