Anyone experienced this b4

Hi ladies,need ur tots,I got a very faint positive line on 14Dpo, which ws on CD 25. My cycle is usually btw 25-28dys. But yestdy Mornin CD 29,tested again bt got BFN bt Later in day I started bleeding heavy , very bright red wit little clots.I have never had it like this b4. I am confused what happened? Cos I had spotting ard 7-12dpo. Bloating, lower abdominal cramps, constipation , full nd tender breast.increasd sense of smell. nausea. Tot I ws pregg, but now. Am bleeding very heavy bright red.did I miscarry