Suggest Treatment For Factor V Leiden Thrombophilia

I have factor v leiden and for the past 7 years have been told I need to take heparin injections that have now changed to clexane, whenever I take a flight. I usually just put in for a repeat prescription when im going on holiday. This time the doctor rang me and said it wasn t necessary I take clexane for my flight and that it was totally up to me to decide if I want it or not. I just don t understand why all these years it has been a must and now its my choice! surely with my condition and family history it is necessary. I just wanted a bit more advice.