Thank you for your question.
If you are due to have a period sometimes this can begin with a light bloodstained or white discharge that then changes to blood. This is not abnormal and is just a variation of how the endometrium can start shedding at the beginning of a period. Its OK to wait up to seven days for a proper bleed to start.
However, if you dont get a period at all and just discharge you may want to consult a gynaecologist if it is over seven days late, and or if you had unprotected intercourse during this cycle.
Rarely if you have been very stressed, lost or gained weight or exercise strenuously ( and you are not sexually active) your periods can become very scanty or you may even miss a few. Whatever the case it is better to be reassured than to worry alone
hope this helps