Hormone question

So at about 4 weeks pregnant I got a hormone blood test done and it was at 450. Now I'm about 8 weeks going on 9 by my calculations. I did another blood test just before I was 8 weeks and got the results today and it was at 135000. The idea of possible twins has come into question because in order for me to be 12weeks( how far they think I am due to hormone) I would of had to be pregnant through 2 periods. Thoughts?