Spotting/period?!

Kate
Hello! I'm new here, only been TTC for a couple of months. My cycle is usually regular as clockwork bang on 28 days. I'm due to start my period in 4 days, but today am experiencing bleeding but can't tell what it is! It's light/medium, light in colour. I usually have terrible cramps on the first day but only had very mild cramps today. The bleeding does seem heavier over the day.
Is it worth taking a pregnancy test or is my body just being cruel & giving me my period early?
I've had so many early pregnancy symptoms over the last 10 days or so, very confusing!