Hi, Welcome to Healthcaremagic, Thank you for posting your query. From the limited information you have provided I understand that you have been diagnosed to have two blood clots in your lungs and have been advised to take warfarin for the same and your current INR is 1.6 and now you have developed pain in your lower abdomen (presumably in the left iliac fossa). To give you reasonably precise answer I would like to know a few more details about yourself and your problems, so if you don t mind, please answer these questions in as much detail as possible, 1. How old are you, and mention your gender too. 2. Do you have any history of cardiac disease, diabetes or any other significant condition? 3. Have been on any oral contraceptive pills? 4. What happened before you were diagnosed with the clots in lungs? 5. Do you have any fever now? 6. Do you have any pain in the lower legs? 7. What diagnostic tests were you subjected to, when you went to the hospital for the clots? 8. Do you get pain in the lower abdomen before each menstrual period? Please do attach any test reports you might have and write back as early as possible. As for now, it is best if you go to the A&E if the pain is unbearable. As you have said, the reason for the pain in your lower left abdomen could be related to menstrual cycle. But it could also be due to other causes like pelvic inflammatory disease (Infection around the ovaries), stone in the ureter, inflammation of the large intestines, endometriosis or blood clots in the veins which go up from the legs. Since there are quite a few causes for your complaints, I would suggest you do pay a visit to the A&E as early as possible. For some symptomatic relief you could try cold compress or hot fomentation. Please do write back with the answers to my questions so that I can help you better. Wishing you good health and speedy recovery. Warm regards, Dr. Yogesh. D