Something has got to give.

I have 2 healthy kids. My son is 8, born when I was 21. Daughter is 4, born when I was 26. I got home from deployment in November and my husband and I have been working on another baby since. I had a devestating miscarriage in February, so when my period didn't show up on 06 June, I was over the moon. Not wanting to chance anything, we have mostly kept it a secret. Last Wednesday, when I thought I was 8 weeks, husband and I had a vigorous session in bed which left me with pink bloody discharge. No big deal, except that's how my last miscarriage started. We went to the ER. After an hcg and transvaginal ultrasound, my level were at 4400 and a gestational sac was the only thing visible. Which would be fine if my dates said I was 5 weeks instead of 8. Well, I held on to the idea that maybe, since my period had been 5 days earlier than normal, maybe I ovulated and implanted later and I really was just 5 weeks. I went back to the ER 36 hours later and followed up. Levels only rose 200 points, and still no fetal sac. They recommended I make an appointment for Monday and follow up again. I started bleeding Friday night. First brownish stuff. And over the last 2 days, a very very slight dark red trickle. No clots or tissue yet. I am in between hoping it stops and I'm able to go in and see my levels are rising and there is a fetal sac, and hoping that it would just get over with. Can anyone relate? We want another baby so bad and I don't understand why this is happening. I'm in great health, and come from very fertile stock. My heart is breaking.