could i be pregnant ?

i been having symptoms like lower back pain , lower abdominal pain i also been having sharp pains in breast which is unusual they arent sore but are getting bigger. i had two very light periods the last two months but today i pose to came on my period but im only having white discharge . i toook aloooooot of pregnancy test before and they all was negative should i take another one now since my period havent came at all or wait ? plz leave feed back thanks