Advise please..

Shauna

So I had my implant removed in April this year and upto now I've had a regular period and they've been pretty much on time with this app. My last period ended September 24th and my next period (according to my app) wasn't due until Oct 17th. This morning I woke upto what looked and felt like my period, only thing different is I feel maybe I'm cramping more than usual? My period is 10 days early. Anyone know why this is or could it be an importantation bleed?