What causes diarrhea and nausea and how can i cure it?

Too many to list: If you had sex since your last period and missed a period, do a home pregnancy test. Visit this site for information about diarrhea: https://www.mayoclinic.org/diseases-conditions/diarrhea/symptoms-causes/syc-20352241 Have a healthy diet, exercise 30 minutes/day, drink plenty of water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs.