Threatened miscarriage

I'm 8 weeks 3 days pregnant and had a week of light spotting over a week ago, it stopped last Thursday. Friday, I went to obgyn and they did ultrasound did blood tests and everything was fine. Early this morning I woke up with blood soaked through my underwear to mattress. Like a really heavy period type and had a blood clot. I went to obgyn and they did ultrasound and the baby is fine, heartbeat at 167 like on Friday. My blood type is negative, so that's also a concern. I've had some light spotting throughout the day but no cramping. Has anyone had a similar situation?