HCG at 4 weeks 5 days = 16,804 Twins?!

Tricia
I tested my HCG at 11dpo and it was 29. I was out of town for a week and finally did my second blood draw yesterday at 4 weeks 5 days and it came back at 16,804. I'm terrified it's twins so am wondering if anyone has ever had hcg this high with singletons? Is that super high? Please respond!