What Causes A Scanty Period Along With Nipple Discomfort?

i have a light brown discharge the day before my period and i had a blood discharge on my exact date of my period. is that a period or spotting? it only lasts for two days and i think it is very light one because i had only consume two panty liners not a napkin. I've experience tingling sensation on my nipples and headaches. when should i get pregnancy test?