But how would i know the difference between implantation an just a normal bleed ! what other reasons that will cause me to bleed twice this month?

May require PCP eval: Implantation can cause spotting, but so can ovulation or an std. If you've had a new partner, std testing may be appropriate. It's possible this is a sign of early pregnancy, but it could also just be spotting from ovulation. If you had full on bleeding, like a period, twice this month, that would be unusual and should you persist in having frequent menses, further evaluation is required by a pcp.