Confused about hcg levels

Stephanie

So I took a clearblue digital at 12 dpo and it said pregnant. I also had a blood test that same day and the results said my hcg was 16. A clearblue digital needs an hcg level of 25 to say pregnant according to the directions. How is that possible then? To be sure I took another clearblue digital the next day and it still said pregnant.