Late period or?

When do you ladies suggest testing after being late? My period is 4 days late(it's different each month so I could be off on this) but I'm having really light spotting(bright pink/brown). Should I hold off testing for another day or is it safe to test today? I had implantation bleeding with my first two kids but it was more than what I have now so I'm not sure if this is implantation or my period trying to come.