Hello,
You should take active rest which means you should not walk/run/jump/play any sports for 4-6 weeks.
If you have developed a stress fracture in the front side (anterior) of your tibia (shin bone) then there is a very little chance for non union. But you don't need to worry about it.
You don't need cast or crutches. Continue your normal daily activities.
Next Steps
After 6 weeks you should take an MRI (not Xray) to ensure the level healing.
Health Tips
Start walking then progress to walk jog for 2-5 km gradually every 2 weeks.