Alright:
It could be a number of things...you could be stressed and that could make you not have your period. But im unsure...

You could also be pregnant....when was ur blood test done?? What day is ur gyno appt???
There are multiple things that could be the reason for your period not coming. And regarding the signs of pregnancy-sometimes the mind plays tricks on you when you first start to think you're pregnant. And then your body reacts...

but as I said I'm unsure. It's my opinion...anyhow if you would like you can respond on my page by adding me. I would like to be of all the help I can.
As I am pregnant myself and if you are I can help you out with all I've been told and know.
Wishing you the best: