I haven't had a period since April of this year. What should I do?!

I haven't had a period since April of this year. What should I do?

Last year everything went well until I had my last period in March. Then this year I had one in April and I haven't had one since. Please help me decide whether I need to tell my mom about it and whether I need to go to the doctor. By the way I'm 17 and overweight with history of diabetes in family.

you stop menstruating if you are very overweight - if you are diagnosed as being "morbidly obese". they stop if you are too thin also.
go and see a doctor. you will feel better about it afterwards. if there is something wrong then the sooner they find out the better.