I had my period twice in the same month. should i be worried?

Don't worry: Worry won't help at all. If this is not just a one time irregularity w/out any other symptoms it may be normal - but if it recurs or you have others, have an exam to discover and treat the cause. It may be a simple hormonal adjustment, but check it out if so. Best wishes!

Irregular Menses: This can be completely normal. Several things influence your cycle, such as stress. Are you on birth control pills and did you forget to take any? Have you had any big fluctuations in weight? Keep a log of when you are starting your cycle and check for a pattern. If it continues to be irregular then should get a check up including labs and an ultrasound