thoughts on my missed period?

hey guys just looking for y’all’s thoughts - i missed my period this month by 2 days now. i saw my long distance bf the last weekend in january and we had safe sex (condom+pull out) but now i have missed my period. i just had the flu and was very sick and undereating for over a week right before i was supposed to get it. also i’m 20 but i’m back to around the weight i was at 17 when i would miss whole months of periods sometimes.

i have been stressed the whole semester because of school but has anyone had stress actually cause a skipped period? i don’t know whether to be worried or not. i appreciate any thoughts or advice!