Gurney
I'm an osteopath in the UK and have suffered the same symptoms as you, known as "intermittent claudication". Mine was due to having been overcooked during cancer radiotherapy treatment 20 years ago but, hell, I'm still alive.
I would consider it imperative for your circulation to be checked by your GP, including a check of all the pulses of the legs and feet, and also any which might be felt in your abdomen.
Suggest you might (slightly) exaggerate your symptoms, such as reducing the distance you can walk before pain strikes, as it may help to get you an early referral to a vascular (blood circulation) specialist for scans. Also try to establish which muscle groups are affected, as each group has a different blood supply.
Try to isolate pain above or below the knee, fromt, back or which side of the leg. Also where the pain first strikes. The doctor will need to know.
You should be put through an exercise routine to check how far/fast you can walk, a form of echo-sounding (Doppler) test to check for roughness within the arteries and possibly a body scan (MRI) using some form of radio-opaque dye injected into your bloodstream. The pictures there, with your blood vessels highlighted, can look pretty impressive!
I would consider it imperative that you refer yourself immediately to your GP, particularly as your symptoms appear to be of sudden onset. If you were my patient I would be making the appointment for you, while you were in my clinic!
While aspirin and coumarins (Warfarin, or rat poison) can be beneficial I would suggest that you should only take them under prescription from your GP, otherwise you may be disguising some problem which may be life-threatening. We would rather not lose you!
I am taking both of those drugs myself and have to attend my GP surgery weekly for a prick test (no, not for that! My finger!) to ensure that my clotting levels have not gone awry.
I hope that the above is helpful. Please come back to me, preferably by PM, if you have any queries.
Colyn.