Early Miscarriage?

Emily
I posted yesterday as a newbie asking about HSG and late cycle. But today I'm wondering if it's an early miscarriage. I've had horrible lower back pain all day ...that goes all the way to the front. I leaked through a pad and down my leg (first time in life) and now I just passed the largest blood clot. I've given birth at 20 weeks before (she's in heaven now) and have an 11 yo daughter so it's been a long time. I don't remember or have never had one potentially this early. The clot was oval but dense and easily about 3 inches ... 😕