I went through a break up a week and a half ago and didn't eat for 2 days and was super stressed and sad. my period is super light this week. is this normal or could this be pregnancy? which is more likely?

Do a home pregnancy test. Use first morning urine. It is unlikely that you are pregnant, but it urine test does not settle the issue, get a blood test for HCG level. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV and Covid vaccines.