Implantion bleeding or period?

My last menstrual period was July 26th, 2017. I was said to be fertile around August 9th-August 16th. my period was due today or tomorrow. I have had spotting and light bleeding since the August 28th. it hasn't been heavy enough to fill up a pad or tampon much. when I would pee there would be some drops but not much. I have had a fullness feeling in my uterus. I have had some cramping but not painful like my normal menstrual cramp. Breast pains started a little over a week ago. I've been craving food I normally would crave. I have had light bleeding for 4 days so far. should I count it as my period and wait for it to get heavier? a dark red but very light flow. advice would be great :D should I try testing soon?