It could be either due to cervical erosion or sometimes there is bleeding even when its an ovulation time or implantation of embryo,in case u are
pregnant.
As regards severe pain u need to wait and get the reason identified for the same , some times seasonal fever or even exertion could be the cause .
Next Steps
observe if these symptoms continue before u take any medicatios
Health Tips
take healthy balanced diet and nutrition supplements,as u may be having
Calcium or
vitamin deficiency.