7 week scan and no baby

Hi, I'm hoping someone can give me an answer to my concern as I'm very worried.
I had my 7 weeks scan yesterday and they could see the sac but no baby. I had blood works done and will get the results tomorrow, I took a pregnancy test which is still positive. I have to go back next week to see if they can find the baby, if they don't they say I might have miscarried. But I've had no bleeding, no pain (just the usual cramps). I'm 37 and this is my first so I'm very scared about next week. Any advise? X