Did you switch formula without PD consultation?

My baby has been having constipation, severe gas pains and fussiness especially after every feed. She also keeps vomiting and crying. Thinking of changing formula but PD is closed today. I’m suspecting it’s lactose intolerance. Did any of you change formula without a PD consultation? Update: thanks for the comments everyone! Going with enfamil AR to try and counter the really bad reflux.