Light flow & very little brown color period for 4 days.

Sabar dulu, sometimes our cycle boleh jadi unpredictable especially kalau ada stress or hormonal changes, a few of my mum friends also experienced brown spotting out of nowhere and turned out nothing serious. Since your UPT negative twice and your cycle is normally 29-32 hari, I'd suggest wait another 3-5 days to see if proper period comes or spotting stops, then if still unusual boleh pergi clinic untuk confirm, they can do blood test if needed which is more reliable than UPT. Mild cramps + light brown discharge yang tak biasa is worth checking out dengan doctor just to be safe, so don't worry la, book an appointment with your GP when you feel ready okay.