Scan update

So I am done with my scan. It seems that Lord willing we will be having twins! However I am very worried. One of the heart beats is a bit slow, near 90 bpm. The other is apparently at 120 bpm.I didn’t like my ob at all. He didn’t even mention the exact heart beats or the babies measurements. He just got me more worried than I was before the scan. According to my calculation I should be 6w4d today. So why are the beats so slow and why is the Dr. being so secretive? I miss my Gynae who had promised to be my OB whenever I would fall pregnant. Now finally after years when I am pregnant, he just fell sick to Cancer. Oh Dear Lord! Save us!