What Do Pain And Cramps In The Calf Muscles Indicate?

I had a fempop bypass to my right femoral artery a couple of years ago. Since then I have recovered quite well, walking 3-4km s daily with no issues. Today I managed about 200m s and the ache and cramps began. Not too severe but enough to make me rest. I am experiencing mild ache in my calf muscle at rest. Should I consult my GP of is this normal? Last ultrasound about 6 weeks ago and results were good apart from some clotting where the graft joins the artery lower down the leg. Previously I has a minor follow up surgery to remove a piece of valve that remained when the graft was first attached.