Late period then spotting?

Hi ladies. I’m new and am just hoping for some input. I have a 2.5 year old and am not actively trying to get pregnant. It’s something that’s hopefully in our near figure but for personal reasons we’re planning to hold off a few more months. I’m not on bc (we just do pull out method) and logic is that I shouldn’t be pregnant this month. But it’s technically possible, I guess, which is what brings me here. I’m nearly a week late, which to begin with is strange for me but crap happens. Then my breasts are sore which isn’t a normal PMS symptom for me. At first I thought it might just be in my head but I’m pretty sure it’s not psycho symptomatic. I was planning on taking a test today but then this morning I noticed a little brown/pink discharge and figured ok my period is here, def not pregnant. Except it’s not blood, just discharge and it seems to have cleared up instead of gotten heavier or turning into a real period. So my question is whether that discharge would be considered a telltale sign of being NOT pregnant or should I still go take a test?