I had my check up at the hospital this morning. Didn't need a scan in the end. The guy heard how it happened, took 1 poke at it and said yup, total rupture. It seems it has snapped a bit higher than usual. He said it normally goes down close to where the tendon attaches to the heel (as seen in the picture below). But mine has gone a bit higher, closer to where it attaches to the calf muscle.