2017 bus information

Hi, we land into BKK at around 9.50. I have heard that there's an 11.45 bus from the airport bus terminal to Trat, not sure if that is correct. I know how to get to ekkemai so if there are other buses from there that's fine but I can't seem to find up to date information, and what I do find, talks about getting to the piers. I want to get from Bangkok to Trat bus station, not any of the piers.

Advice gratefully welcomed please..