You may have exacerbated your initial calf injury. A common observation is that the patient and more often the physiotherapist gets ahead of the actual healing process i.e. doing too much, especially at the stage where the torn muscle fibres have just sealed. You would need to rest for a few days from prolonged walking, stretching and doing strengthening exercise (if you were given some to do). Check with you doctor to rule out anything untowards and get some Wikipedia reference-linkanti-inflammatory medication to settle the calf pain down.

Good luck.
M.