Thanks for the query to ATD for an opinion,
If you had your menses last month which were late but they came and lasted for 3 days, then it is unlikely that you would be pregnant and the delay would most probably be stress related induced by a hormonal balance. The pregnancy symptoms in the form of nausea, fatigue, headache, sore breasts can be due to the effect of progesterone in premenstrual syndrome or PMS.
It is however suggested that a blood serum beta hCG test may be done which can detect levels of hCG in the blood. If the levels are more than 1 or raised, then it indicates pregnancy but if the levels are less than 1 it rules out pregnancy confirmatively. In the presence of a negative pregnancy test, the symptoms are more likely to be PMS and not pregnancy.
I hope I have answered your query in detail,
Wishing you good health,
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.