High hcg levels

Found out a last wed that we are finally expecting again after a Mc in june. My hcg levels ate amazing and people keep saying twins... scaring me haha. Last wed they were 437, on Fri they were 989, and then early Monday morning it was 4,000. It more then doubled. Yes it had been 72hrs instead if 48hrs but that's still way more... could it be possible of twins? And since we were ttc I'm thinking I'd only be approximately 3 weeks as I ovulated 2nd 3rd 4th of this month. Any thoughts???