RE: 90 days report

I always thought that if you leave Thailand and return, then 90 days starts from the date of return.

So in my case, my last 90 day report was March 9th 2017 - and my next date was supposed to be June 6th 2017. However, I left Thailand in April and came back on May 9th 2017. So all along I presumed that another 90 days started on May 9th and that I'm due for the 90 day notification sometime this month (August).

However, someone just told me that that's not the case anymore and that I should've gone in June. Is this correct???