Have I stopped ovulating and should I be concerned?

I’m in my early 30s and all my adult life my periods have been like clockwork. 28-30 days cycle with a medium flow lasting roughly 5 days, with the odd heavy period every few months. Symptoms just before it starts that indicate it’s coming like cramps and breast tenderness. I’m not on hormonal contraceptives and haven’t been for years.

My last period in March came slightly early and was light and only lasted around 36 hours with no warning symptoms before. I had been through a period of stress from late November until mid February and flown a long haul flight in February so put it down to that and expected my next cycle to be more normal.

Following my normal cycle, my period should be due in roughly a week. I noticed today that I have spotting (some brown discharge on my underwear) which is not normal for me I’ve never had spotting before.

I was going to take a pregnancy test tomorrow but I have not had unprotected sex and no condom failure so the chance of that is extremely unlikely, plus the fact I have a child and have had an abortion before and I do not feel pregnant no fatigue or heightened sense of smell or nausea that I got at the start of previous pregnancies.

Could that stressful period of time still have an effect on my cycle now? Is this normal to happen sometimes? Or should I be alarmed?