I went to yoga on friday and after the class i noticed a sharp pain near my tailbone when i move. what should i do?

Muscular : Probably muscular. An anti inflammatory and local heat application may help but it should be self limiting and gradually go away

Time: Very likely this is a soft tissue strain and given your age it is also likely that this will resolve quite rapidly by itself. If you need to, you could take some paracetamol and/or ibuprofen for the discomfort. Otherwise, keep gently active with walking but avoiding too much sitting, heavy lifting/bending.