I'm nervous and need advice!

I was due for my period on Oct 14th and I haven't gotten it yet. In August and September I got it like clock work on the 14th and both lasted the same 7 days. Today and the past two days I've experienced spotting (light pink and brown) and I'm wondering if it's implantation bleeding. My glow app keeps pushing back my period and says that I have three more days but I'm already over a week late. I'm nervous because I'm reading articles that say implantation bleeding happens before youre supposed to get your period and also it should only last a few hours or on a rare occasion up to two days at maximum. Is it worth taking a pregnancy test? Is there something wrong? Or am I going to to get my period soon? Has anyone experienced this?