Have you had a test yet? Have a test to put your mind at ease. Did you know that stressing out about stuff can make your period late and can even make you skip a period. It is your bodies way of saying ‘whoo back, i’m feeling a bit overwhelmed here’.
In regards to all of the other ‘symptons’ I think you may be feeling these symptons out of the thought of being pregnant. The mind can do some pretty amazing stuff.
My advice is to chill out, try not to stress to much, take a test and see what happens. If the test comes back negative then you can stop worrying which will (i’m sure) let your body relax and get back to normal.