Hi & Welcome to HCM.
Incomplete data like age, marital status, expected pregnancy, etc???
When experienced outside of your normal menstrual cycle this unexpected bleeding is considered to be 'Mid-cycle bleeding'.
Midcycle bleeding can be due to
implantation bleeding, hormonal disturbances,
endometriosis, abnormalities of the cervix, rupture of the
ovarian cyst,
miscarriage, etc.
The symptoms given in your query are suggestive of implantation bleeding.
For this please check your pregnancy status using a urine pregnancy test at home. If it is negative then you should get your hormonal profile including thyroid hormone levels checked and get a
ultrasound done to confirm the diagnosis. If it is positive or if you have any pain/discomfort then it is better to consult a obstetrician as soon as possible.
Hope you found the answer helpful.
Wishing you good health.