ovulation and CM discharge question

Jillian 👣 praying for our 🌈

So I am in my fertile window. I took a OPK this morning it said I wasn't ovulating. This afternoon (tmi) I went to the washroom and had a brownish cm discharge (which I've never had it tinted this color before). Question... is it possible to say I wasn't ovulating this morning and to now later in the day be ovulating? If so I need to change my evening plans and go do the BD!