Should I Test? Advice?

Hey y'all! So this is my first time actually "TTC" (not really trying but not trying to prevent it either). I'm not really sure if or when I should test. I'm currently about 4 or 5 days late which should be about 18 dpo. I did have the tiniest amount of spotting a couple days ago (like barely even there and wouldnt have noticed it at all if I hadn't been checking for my period) but haven't had any other signs that Aunt Flo is going to make an appearance. My periods are extremely regular and always start when theyre supposed to and end when theyre supposed to, give or take a day. I've kinda just been waiting it out to see what happens but this waiting is H E L L.