Hi,
Usually with hamstring injuries walking is painful but you can try and jog, it should not hurt in ideal scenario. Also see if there is any swelling over the hamstring or not. Depending on that you may put heat or cold on it. If there is swelling put ice on it for ten minutes and if there is no swelling you may put heat for ten mins and gently try and stretch out the hamstring.
This should give you considerable relief.
Next Steps
And if you can go a see a physio asap that would be really really helpful for you.
Health Tips
Avoid running and sprinting till your pain and discomfort settles.