Here it comes again :(

It's just 20 days after my last mense, today it comes again.............for god's sake, can't i just have regular menses?? I have come for 3 weeks the last time, now it come again. I have already on medication, what is wrong with me. Damn sian. Totally no mood, no wonder for the past one week, i am having PMS, feel like punching people. Everything also gets on my nerve. Argh........