Hcg levels have tripled and that makes me nervous

I went in at exactly 4wks and my hcg was 335. I was thrilled as this is in "normal" range. On 4wks/2days I went and it tripled to 1015. I'm scared now that that is too much. "Normal" for 4 weeks is 5-426. I read high hcg can be indicative of a molar pregnancy or Down's syndrome. Has anyone had hcg levels like mine so early on and had a normal healthy baby? I don't think I am off on my ovulation date. I'm so nervous.