Speechless maybe twin baby

went to clinic scan..doctor informed me now I'm 7weeks 5 days..I can hear the heartbeat & see my baby heartbeat..I'm cried ..but make me much more speechless, maybe my baby twin..WHAT??. but the 2nd baby cannot detect the heartbeat . me & doctor can see 2 entity..2nd baby small then 1st baby..so doctor not sure I am twin pregnant or not..who have experience same as me..please share..I'm so nerves..need to wait another 2 weeks scan again to confirm twin or not