Anyone know about yeast infections?

Mospa • Mommy to a 2yo boy. Clomid treatments, and had a mc 2 months ago, now newly pregnant again. Stick with me, little one!
I'm not sure if we have a yeast infection.  I had mastitis and took antibiotics and a pill to prevent, but now I have pain in both breasts and he is gassy and irritable, but no white patches on his mouth/tongue. Should I go to the pediatrician or my doc? Anyone else been through this?