Hello mam, thanks for trusting health care magic.
In my opinion as your urine pregnancy
test is negative get a pelvic ultrasonography
and b HCG
testing because it can be an early pregnancy or worse ectopic tubal pregnancy and then visit a gynecologist with reports. stress
can cause delay in periods definately but not this pattern of bleeding.
specially when you are getting this dark altered colored bleeding.
In case you have further questions you can consult me on health care magic forum and i will be happy to help
Take care and wish you all the best.
Dr Manisha Jain