i stopped menstruating entirely, it's been four months

basically yeah - i've stopped getting my period entirely since 2016 began. at first i was worried and took some pregnancy tests, even though i knew there was a near zero chance that i could have become pregnant. two different times in march, came up negative. been feeling all right, eating healthy food (meat, carbs, veggies, low sugar, but i do drink a lot of coffee), and been a bit stressed due to life circumstances but not much more than i would expect. actually, everything feels basically completely normal except i stopped getting my period. i don't think i have any of the early signs of pregnancy, tho i'm not actually entirely sure what they are. i haven't been exercising *that* much. i've heard it's semi-common for this to happen. i don't have insurance but i'm going to new york in june where i can visit a doctor at planned parenthood for free. so that'd be in another almost two months. is there any reason i should rush to see a doctor sooner than that? i'm just out of college and i have very little money so i'd rather just wait. it's just all very mysterious but my guess for the cause is just stress.