As you said the teeth of the calf grazed your finger slightly below the nail, and from your explanation i think the part which has been in contact with the calf is intact. No bleeding or broken skin.
Your main concern is that you touched your forehead where there was a pimple with broken skin. So do you need to take the anti-rabies vaccine or not? When did you washed your hands? After touching the forehead or before? In either case you need not have to worry. You have already done what needs to be done.
Next Steps
If you are still concerned about it and very much worried. Then you may get yourself a TT injection for now. That's all you need now.
Health Tips
If you are having frequent interaction with pets or animals around then it would be better you get an Anti Rabies vaccination done.
This could be the solution based on what you have written here. For a more detailed review please do consult. Need to see the broken skin and part.