Missed period...

Hey guys! So I am 2 weeks late for my period, I took 3 pregnancy tests, all negative. I had all the other period symptoms though... the fatigue, some headaches, tons of cramping (all the usual stuff for me). In all of the years I have had my period, this has never happened. I have been on birth control for 2 years and take it religiously, have never missed a dose and always take it at the exact same time each day. I have also noticed that in the last 6-8 months, my period has been getting shorter and lighter each time. Anyways... I am super nervous about being late....Is it concerning or is it normal to miss a period? Could this be because I have been on the pill for so long? Advice please!!