HCG levels

Okay so I've known for about a week now that I'm pregnant 
My HCG was at a level 10 on Thursday
And today is a level 19.
Has anyone experienced low HCG and still had a healthy pregnancy?
I'm also bleeding but no clots and cramps.
The calculator said I was 5 weeks
But the doctor said based on my results in either not 5 weeks and barley 3 weeks or having a miscarriage. 
Anyone experienced the same?