I had my period for just one day.?

i am overweight. my doctor suspected thyroid and PCOS, but i didn't have it. it was revealed that i had a smaller uterus. she gave me medicine for regulating periods. for almost 9 months the cycle was fine untill 3 months ago when scanty periods started again. i again got an ultrasound done which said that the uterus was normal but there were peripheral small follicles in the ovaries. however, this time the uterus size was called normal. i had this test done just before my period last month. Now the other doctor suspects PCOS. i didnt have my period this month and is delayed by almost 15 days. i am also very stressed out(almost depressed) these days because my parents have suddenly become non supportive in my career. i cannot pursue the job of my choice. in fact i was called back from Delhi just after finishing graduation and i was already getting good jobs there. an otherwise outgoing and free communicator, i have limited talking to my friends . my physical activity is also quite restricted these days. i get a few cramps every now and then, which makes me feel that i will get a period but that doesnt happen. otherwise, i get a 3 day period without any pain and almost negligible cramps. any suggestions? i doubt that PCOS is not really the case and this condition is because of my mental stress, change in the everyday pattern and physical inactivity. And which doctor is right?