Did I miscarry ?

So I was 3 days late for my period & on the fourth day in the afternoon around 5 pm I started literally pouring blood …. With chunks and chunks of clots …. Could this mean I miscarried?🥺 my body has been in so so so much pain … heartburns , lower back pain , & lower abdomen pain right beneath my belly button … should I be worried ? Did I miscarry or what could this be ? 😭😭😭😭 my fiancé and I aren’t taking this too easy … we’ve tried for at least 4 years & still no baby . This is the first time we thought we were actually pregnant … first time in forever that I missed my period & we were overly excited 🥺 . I’m so heartbroken .