Nervous and Worried

Jennie • I am married with an almost five year old baby boy, and baby girl on the way!!!
Okay so this is my second pregnancy, and my first was terrific, I never had any real problems or complications. However this time around I'm very worried that something may go wrong, in my first pregnancy it was only me looking forward to the birth of my son, his father had taken off, but now I'm married and I don't want to disappoint my husband. I'm worried at my first appointment tomorrow their may be no heartbeat or something wrong, I don't want to lose this baby. Is it normal to be this worried yet anxious and happy all at the same time!! :/