Anyone else been told they have a blood clot in their uterus?

Sunday I went to ER because I was bleeding they ran some tests did an ultrasound and I was told it was a cyst on my ovary. Well I follow up with my doctor 3 days later and have another ultrasound the tech asked if I knew I had a clot and I said no afterwards we meet with the nurse practitioner and she tells me the blood clot has doubled in size and I’m on pelvic rest and can’t lift over 5 pounds. I go back in 2 weeks for another ultrasound to see if it has gotten smaller or bigger if it’s bigger I will be put on bed rest. Feeling scared I’m only 9w4d this is my fifth pregnancy and I’ve never miscarried. My last son was emergency csection at 34 weeks due to pre eclampsia and I read where these clots happen is an indicator of pre term labor. Thoughts? Experiences? Baby’s heart rate was 177.