Whats the last 3 cycles been like? I recall mine extending from 28 to 34 in 3-4 months whilst ttc, where the last one had cramping symptoms a week before period was meant to arrive and I got a positive after one day late. Stress is 'invisibke' sometimes, so you may have things on your mind that are worrying you. Hope for the best for you!
I haven't had any major stress recently and stress has never made me miss a period before so I don't think it's that.
Could be stress related? Stress can sometimes alter your period
Sorry negative not positive