6+1 Weeks Pregnant

Mary
Yesterday was a pretty traumatic experience with a happy ending this morning. I went down to my sisters about 2 hours away to see my niece graduate. Sat in traffic for 3 hours and was cramping a bit but thought it was from sitting for so long. Pee'd when I arrived and no spotting or anything when I wiped. Continued having cramps during the ceremony and once I got back to my sisters house I went to the bathrooms again. Red spotting.....the previous day I had gone to my fertility clinic for my first ultrasound and saw the baby and heartbeat! First thought was maybe the  wand they used for the u/s bumped my cervix and that was causing the bleed. 
Went back to the family gathering and felt a rush of something down there, rushed back to the bathroom and was bleeding heavily. I passed a rather large clot (ping pong ball
Size) and thought for sure I had miscarried. My sister gave me a pad and a change of clothes and  left late that night to drive home with the intention of going to the ER first thing the next morning with my husband.
Next morning we were admitted right away and after a couple hours at the ER doing tests and ultrasounds, the Dr gave me the most beautiful news. She said our baby is measuring perfectly at 6weeks1day with a strong heartbeat of 124bpm. HCG is 24558 and my cervix is closed. I am going to follow up with my OB on Monday. I'm so greatful to the staff at the hospital, for my sister and my husband for all taking the best care of me and my baby. 
I have had absolutely no bleeding or cramping since I passed that clot. My only thought is that it was a subchorionic hematoma, but the ER Doctor didn't see any sign of it or at least any more. 
Thank you God!