Unprotected sex & bleeding a week later?!

I had an unprotected sex October 1. He "pulled out" & yes I'm aware you can still get pregnant. But, about a week after I had very light bleeding for a day & a half. I also should've gotten my period around the 15th-18th. My cycle is not super irregular sometimes my period just comes either a couple days earlier or a couple days later than it should. But, I still have not gotten a period & a couple things I am experiencing are being hungry, tired, having terrible indegestion & gas. My areola's have always been so light too & the past 3 days I've noticed they are getting a little bit darker tan color. I'm wondering when I should test... thanks in advance.