Late periods over stress???

this is not my current situation but it was my situation a month or two ago. I was freaking out because I missed my period for two months and my paranoia caused me to think of every little thing I experienced with my body as a pregnancy symptom. eventually I took a test and it was negative and I got my period a week later. but my question is, what would have been the cause of that two month delay? I was quite stressed due to sudden changes in my life but I also compared it to times before when I was overly stressed to the point I started growing white hairs and my cycle was normal? has anyone had the same issue?