Question!!

So I honestly can't remember the exact day(s) DH and I had sex because I forgot to log it.. however, for 3-4 days now I've been spotting very light pink and only when I wipe. I took a test 3 days ago and it came back negative. Today, I woke up to brown spotting instead, and again, only when I wipe. I'm supposed to get AF on Wednesday. Any of you ladies experience this and can you tell me what I should do?