confused

Amanda
Has anyone here had a faint positive but blood work be negative?
My IUD was removed 14 days ago today. I took a test on day 7 (just playing around) and had a faint line. So I took 4 more and they were all faint. My HCG was 5. 
I took a urine test today and it was grossly positive. I Hv labs again on Thursday. 
I realize that a fetilzed egg will stay in Fallopian tube for several days and then it will need to attach itself into the uterus. I've read that it could take 9 days to complete that process.