Chemical pregnancy

Megan • Happily married since 9/29/13
I had two BFP two days apart, 4 days after my missed AF. 3 days later I started bleeding heavily and cramping in the middle of the night.  I've had an ectopic pregnancy before so I was worried. Hubby brought me to the hospital and they gave me a urine test which was negative. The ER doc said I was just getting my period and that was the reason for the blood and cramps. My OBGYN is still giving me a blood test next week to be sure, but she thinks it was a chemical pregnancy. This is when the eggs gets fertilized but doesn't attach causing a miscarriage. Tonight in shower I definitely think it was a miscarriage, I was bleeding out clumps of skin and things I've never seen before. Anyone ever hear of this? What is going on with my body???