Upset. Mc, preg, possible mc#2

I'm so upset. Just found out I am pregnant 5 days ago. It took 9 days to get a pos test so that concerned me from the start. I should be 6.5 weeks according to my last period. I had a miscarriage/d&c two months ago so you can imagine how worried I am. Went to the doctor today and we couldn't see anything. He said he wasn't concerned, he said I'm probably just not as prego as I thought..especially because it took so long to come up with my bfp. (ya right, he just didn't want to freak me out anymore than I was.) We took my hcg levels and I will be hearing back in a few hours. I am just so upset nothing can go right. Why the hell did I have to show a bfp? Why couldn't it have been easy and just need a bfn? I am so lost, upset, crushed, and exhausted from all these bad things. I just want my baby! ;( Shouldn't I have been able to see the sac if I'm only around 4 weeks?