Hellllppppp! Light period


My last period was 7/25. Not to mention it came about a week early and was a heavy flow. (According to my charts I was due the 22. I got off the iud about 6 months ago so Idk if maybe that has anything to do with this but I've been ttc ever since. Well it's the 29th and I got a very light brown spotting! I ovulated around the 6th. What could this be? I'm afraid to take a test and have a negative šŸ˜” should I wait? By when should I have a heavier flow if this is my period? I noticed the blood last night when I was checking my vaginal discharge and it was very light bloody.