Weird Cravings

I’m currently 33 weeks pregnant and since I’ve been about 25 weeks I’ve had this weird craving for corn starch and baking soda.... I’m really embarrassed to talk to my mom and doctor about because I’m scared they’re going to think I’m crazy and it’s not a everyday all day thing it just pops into my head randomly and it’s like I haaaavvvee to have it. Am I harming my baby??? Will it cause him to be born sick or anything???