Testing and irregular cycles

Allison

Hi everyone! I turned 40 in November and just went through a miscarriage at 8 weeks in September. Since then, my cycles have been off. I had a light cycle in November, two heavy cycles in December, a regular cycle in January, no cycle in February, and then my March cycle was early and last 11 days. If my March cycle started on March 6th, when would I test for this month?