Previous MC now Faint BFP at 4wks

Meghan • It's a girl! Kaylee Marie! Due date 11.22.15 =)
Hi, I just got my bfp today. And I'm 4 wks 2 days. I'm worried bcuz the line is pretty faint for being 4 wks..I had a MC in sept and am just worried this means my HCG is low and isn't going to be a good strong pregnancy and going to have another MC :( anyone else have a faint line like this at 4 wks and go on to healthy pregnancy? Still won't show on digital. Called dr office and they don't want to do lab work or anything just wait and come in at 7 wks for lab and ultrasound. Unless I start having severe cramp or bleeding like last time. Thanks :)