Heavy bleeding not af

hi ladies, I really need your help! I am really irregular with my periods! My last period was 27th December 2015 and I had to wait 76 days for that!! My whole life I can't remember having a period less than 30 daus (usually over 40) but this month I came on on Monday 25th January!! (28 days) based on a 28 day cycle it means I would of had sex on my ovulation date on the 16th January. When I say I 'came on' when I wiped on the Sunday there was a tint of pink in the paper, then when I woke up Monday morning I was heavy, but it was like really red watery liquid and had no pain or normal period symptoms. This lasted 24-48 hours then went really light. I'm trying to figure out what it was?! Being hopeful I would love to be pregnant, but I'm wondering can it be implantation bleeding? Is it normal af? Is it an early miscarriage? So confused, but my heart is telling me it's not a normal af. Any advice would be appreciated xxxx