My little bean

I went to the ER yesterday after noticing I was bleeding at 7w5d. Trying to keep myself calm and collected was not happening as all I could think of was the worst. They did blood work and a transvaginal/abdominal ultrasound. As they saw a sack, but no yolk they confirmed I was having a MC. They told me to come back in 3 days for a D&C in case it doesn't naturally happen on its own. I've never felt so heartbroken and emotionally empty. These things happen for a reason, but it's not fair. My question now is approximately how long will the bleeding occur if it were to happen on its own or even after D&C? When should we TTC again? Thank you.