Bleeding and clots

Wend to do progesterone labs yesterday afternoon, levels were great at 21. But I ended up in the OB ER last night. I was in the shower and started bleeding.... ***TMI*** Blood was running down my legs, I was sure I was loosing my baby. Sat on the toilet and a huge clot the size of my palm came out. I just knew my baby was gone. BD rushed me to the ER. They did a pelvic exam, my cervix is closed. Had an ultrasound, my baby was bouncing around and heart rate was 169. Thank you Jesus!! But I am still trying to figure out why I keep having these bleeds. I passed a quarter sized clot two weeks ago at 9 weeks. They said it was a subchorionic hemorrhage. I had just gone Monday for ultrasound to make sure there was no more blood. Everything was great, But last night it was so big I was scared to death! I went and did progesterone labs again this morning, waiting on results. Has anybody experienced this in the first tri? I am 11w1d baby measuring 11w3d. This bleeding is freaking me out!!!