I’m very worried about this new mole

I understand I need to see a doctor and I am going to contact my sons doctor on Monday. I just noticed this black mole that I have never seen before on my sons foot. My son has always had that brown mole ever since birth but this is a new mole I just noticed this morning. It’s driving me crazy and I just want to see his doctor asap 💔 I’m scared that’s why I’m trying to see if I could get any advice.