My period was supposed to start on the 13th of this month. On the 19th, really the 20th, I started a really light bleeding - the color a strange red/pink, almost maroon. I have little-to-no cramping which is highly unusual for my periods. Lately, I am feeling tired, hungry, and my nose has been runny even if I take medicine. My question is this: If this is implantation bleeding, how soon can I test?