I can understand your anxiety. But since you told me that you have passed a small quantity of fresh blood, it could be probably due to a delayed period. It may also have been delayed following stress. It should start in a few days or so. However, if it doesn't resume in 4-5 days, you can consult an Obg-gyn doctor.

In regard to your question on the pregnancy test, usually there is a small percentage of false negative where it is seen in three conditions:

a) You have tested 6-7 days after ovulation using a home kit. In such a case, the test appears negative, as there is not enough HCG in the urine.

b) Urine is diluted as the patient as had a lot of water, so the test appears negative.

c) Sensitivity of the test is low as seen in home kits.

I would suggest you meet the doctor and get urine pregnancy test along with HCG levels and consult them with the reports.