faint positive then BFN

received a faint positive a day ago and then Bfn the day after. now am feeling unusually sick like am about to catch a cold. been having slight diarrhea for the past 2 days and on and off nausea n consistent tiredness. The symptoms aren't intense but I have never gotten a faint positive aka almost positive before nor have I ever felt like this so early before a period. my AF is 4 days away. I don't wanna get excited but that faint line was there within its time frame n I can't seem to get the maybe I'm really pregnant thinking out my head... Am not ready to test again cause i wanna wait to see if this really is real or not you know.