all signs of pregnancy to me...but stress can cause missed periods , but you need to see a doctor, if the tests all come out negative there could be something else going on inside and you dont want to leave it wait. believe me, i did not have a period for 3-4 months due to high grade cancer cells that caused lesions ...go asap girl.
you may be pregnant, go get a blood test to see for sure and talk to your doctor.