Missed period or implantation? ? Either way im sad

My period was due last week monday. Throughout my 15 yrs of having a period she has never been this late. So naturally i got excited over the idea of thinking im pregnant. I went to pee and now im not sure if its my period or implantation bleeding but it really put a damper on my mood and now i just want to curl into a ball and cry. Am i overreacting? A huge piece of me think i could be but seeing blood has me feeling all the way down. What do you think