Hello. I am on an 8week injection since Nov2010. My period stopped for a few month but then came back a couple months later. I received my last injection on the 21st of August and spotted for 1 day on the 6th of september and spotted again for 1 day on the 7th of October. Why am I spotting for 1 day 2months in a row? My next injection is due the 19th of October, should I take a preg test before I get my next shot?