These can be pregnancy symptoms- but they can also be caused by many other things. Have you taken the test recently or was it a few weeks ago? If you took it a few weeks ago, I'd test again- however if you just tested and it was negative, it's not likely you are pregnant. Late periods can happen for tons of reasons- even something like stress, so check back with your doctor on why they think you are late if that blood test comes back negative (which it likely will).