Talk to Gynecologist on Missed Periods

Last periods started 10 feb. in march, April it’s missed.. didn't feel cramps in march but from 3,4 day it feels like back pain and lower abdominal pain but nothing happens.. isn't married yet previous cycle was 46 days, she is worried about increasing weight. No one is taking to doctor saying its normal sometimes to miss periods. She started getting depressed whether its pregnancy but how it is possible without marriage or thoughts like that are irritating her. what should she do...