This is the first time I've felt nauseous before my period but I'm due on and felt like vomiting since yesterday, especially in the mornings around 10:00-12:00

I don't know what to eat to settle my stomach, I tried salty crips which used to work with travel sickness for me but the oil made me feel worse. I've put a sweet potato in the microwave because I read that starchy foods help but I have no idea what actually works.

What do you eat? What do you find works?

(+I'm definitely not pregnant before someone suggests that)