When you found out you was pregnant did you just have a feeling it was twins?

I got my nexplanon brith control taken out at the beginning if August an got my bfp on September 24th. So it happened pretty quick an i found out really early. My hcg count was at a 40 so the dr said i was about 1 week pregnant an couldn't belive i got a positive test that early. Ive heard a few things about twins. Any advice?