Missed Period

Has anyone experienced just a random missed period? My period is usually during the last week of the month and it decided to go missing this month. I've taken 4 pregnancy tests between last week and this week and they're all negative. I won't be able to go to a gyno until next month due to time constraints. But I am on doryx for my acne (which has caused my period to be late before) and I am under a lot more stress than usual due to work. Plus I practice jiu-jitsu... For me, it's pretty obvious that it's a combo of all three affecting me now but just curious to others' opinions. 😊