I entered Thailand on Dec 5 with a visa exemption valid until Jan 3. I alredy extended this exemption until Feb 2 at immigration. If I now fly out of Thailand on Dec 31, so before my extention starts, do I need to do something, like cancel my extention? I plan to re-enter Thailand by plane on Jan 10. And than will stay until Mar 31 in Thailand, so I will do one more extension and one more border run or fly out/in.