I took the morning after pill mid november and had an irregularly heavy period two weeks later. i have not had a period sense but have had a small decrease in weight and an increase in stress? could this be linked or is there possibility of pregnancy?

An "expected period" two weeks after the "Plan B" medication is appropriate, but to be certain about possible pregnancy, obtain a serum HCG test, and see your GYN physician if positive.

If you had sex since your last period, do a home pregnancy test. If the result is negative repeat, it 4-5 days, unless you get a period by then. Get HPV vaccine. Wish you good health! Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines