Advise please

So AF is here 4 days early, cramps are horrendous but my period is like dark red blood mixed with a sticky clear substance. We’ve been trying for a baby for a while now and none of my periods have been like this before. It’s not filling tampons after 2-3 hours wear and it doesn’t seem to be getting heavier as the cramps get worse. Is this just a weird AF or has anyone experienced this type of implantation bleeding?