Breastfeeding question

My baby is almost three weeks old and unfortunately due to some issues that went with the birth, my body was under some stress and I was unable to start breastfeeding right away. As time went on I continued using formula but now I’m finally feeling comfortable enough to start trying to breastfeed and pump. The issue is I never had my milk come in as I wasn’t doing anything to express so I’m unsure if I’ll have a supply. Is it too late to start breastfeeding and pumping, is there anything I can do to help the process?