So confused, what is going on

OK Guys the above is a screenshot of my cycles from my iperiod app. I have been using this app for over 2 years longer than I've been using Glow. My period is 4 days late and I've been experiencing mild cramps on and off I've got sore boobs so I did a test yesterday afternoon and got a BFN. as of last night I've been getting constant cramps, went to the bathroom last night and wiped and saw light pink blood thought it wasn't period so I put a pad down. Woke up this morning and there's literally like a spot of blood on my pad but normally my periods are heavy and dark red. When I wiped there was more blood but light red this time. Am I to assume because I got a BFN I'm out again this month. And this is just my period 4 days late ?