Twins!!

I'm super worried rt now. It shows my husband and I are having twins we are so excited. But still very worried that there isn't heartbeat or heartbeats yet. The doctor is having us to wait a bit longer to check again. She thinks it still might be to soon. Because there is two babies instead of one. I'm 7wks4 days. Going off there's and mine calulation. Also my husband is deployed rt now so I'm all by myself wth our beautiful son he's 1yr 4mths. God I hope and pray so. Today I did have a lil brown spot on top of everything. I still have all the symptoms.