Implantation bleeding or just late period?

I’m 14DPO, but 2 days late for my period. I have never been late before in the last 6 years. My periods are always extremely heavy days 1-3 and then light after that. Been TTC for six months...

UPDATE: it’s very bubbly and diluted so I’m even more confused.

ANOTHER UPDATE: so my entire life of periods (the last 10 years) have always been extremely heavy, and dark, I usually go through 6 super sized tampons a day. I’ve used 2 light flow tampons today and really only needed 1. Could it still be implantation bleeding? I read that it can mimic a period.