Implantation or menstruation?

Sana mapansin at mabasa po ninyo ang nararanasan ko ngayon, dahil hindi na po talaga ako mapakali. I experienced bled 7-10 days before my next period. I share my experience, July14-18 was my last menstruation, then I bled from July31 until Aug9 and I don't know if it's menstruation because there is only a small discharge I don't know if it's implantation bleeding or menstruation, my period is regular monthly then the expected date of my next menstruation is Aug11-15 but I delayed for 3 days I already tried pregnancy test, it was negative. When can I use a pregnancy test? Hoping to have a first baby.