Found the solution myself if somebody is interested:
$.fn.dataTableExt.oApi.fnPagingInfo = function ( oSettings ) {
return {
"iStart": oSettings._iDisplayStart,
"iEnd": oSettings.fnDisplayEnd(),
"iLength": oSettings._iDisplayLength,
"iTotal": oSettings.fnRecordsTotal(),
"iFilteredTotal": oSettings.fnRecordsDisplay(),
"iPage": Math.ceil( oSettings._iDisplayStart / oSettings._iDisplayLength ),
"iTotalPages": Math.ceil( oSettings.fnRecordsDisplay() / oSettings._iDisplayLength )
};
}
And then:
var page_number = datatable_test.fnPagingInfo().iPage;
datatable_test.fnDeleteRow(datatable_test.fnGetPosition(row), function(){datatable_test.fnPageChange(page_number);}, false);