Af or implantation bleeding

I've been spotting on and off for the past 5 days. Only 3 times out of these past 5 days I've needed to use a panty liner. The blood has been mostly brown and occasionally showed up like a dark red to light pink. My period is irregular but my flow is always the same. I always have a heavy period with major cramps the first 2-3 days. These past few days it's been light cramping that's more annoying. Today I noticed I spot whenever I've been feeling little cramps. No blood clots what so ever, which is also unusual for me during my cycle. Any insight would be very helpful for me! I'm praying for a positive test after the spotting stops! I took one during day 3 and it was negative, but I also read it could be too early, that I should wait a few days after bleeding/spotting stops.