I am on periods and my lower abdominal is paining badly. Legs and lower back is also aching badly. This is the first time it is paining in such a way, i have gained 4kg in last 4 months after marriege. Suggest me what could be the reason for this and how i can cure it. Also cycle is not regular it varies from 29 days to 36 days whereas the avg is 32 days, sometimes it also skips, that happen once in a year(hardly).