Implantation bleeding

Lissette
My period started jan 9 and finished jan 15-16 As per glow I ovulated on jan 24. And yes I had sex on the days that glow stated I was fertil so today at work I went to the bathroom and when I wiped I had brownish pinkish spotting and my boobs/nipples are hurting a lot and they feel heavy very sore. Also I have some mild cramping and lower back pain I'm suppose to get my period on feb 7 or feb 9 
Im not sure if this is implantation spotting/bleeding I put on a pad just incase it ends up being my period instead . Has this happend to anyone ?????