I'm losing my sanity

I'm 15+2 but I'm nonstop thinking about if my baby is still okay in there. I have a doc appointment on Wednesday but I'm constantly worried. I know there is no way to tell unless I get an ultrasound or the doc uses a doppler to hear the heart beat. I'm such a nervous wreck all the time. Can't stop thinking about it. Anyone else feel the same? What can I do to calm myself down