Formula fed baby isn’t pooping

Kami

My LO will be 1 week on Friday and is formula fed. I feed her Similac sensitive and hasn’t pooped since Tuesday night! should I be concerned? she isn’t fussy or her stomach isn’t hard she doesn’t cry unless she’s hungry. I called her doctor and they suggested to insert and a q-tip into her butt and try to get her to go like that! Has anyone tried this and it worked? Any suggestions?