Worried

My daughter just turned a month old on the 10th. She was doing half breast milk and half formula. My supply basically disappeared and I start a new job Monday so I won’t be able to keep up. She’s been on more formula now than breast milk. Anyways, she’s not pooped in 3 days now and I’m super worried. She’s only a month old so I figured water or juice was not right. Her next appointment is in a week, I’m a first time mom and I’m not sure what to do. I don’t want to call I feel silly for it. My husband does if she doesn’t tonight what can I do to give her some relief? We tried bicycle kicks, tummy time, a warm bath, stomach rubs and patting her back.