Hi, Thanks for using HCM.
Since your test was negative chances of pregnancy
are minimal. If you had noticed passing any tissue in bleeding get USG abdomen done for intrauterine endometrial thickness.
Get PAP smear
done, a screening procedure for cervical pathology.
Delayed periods could be due to hormonal
Consult your doctor for examination and management.
Hope I answered your question. Feel free to ask me if you have any further queries.
Wish you good health. Take