Regarding my periods. What can be done?

I've been having difficulty getting my periods this month. I'm late by 12 days and it hasn't happened like this in over 4 years. For the past 2 years I've been very very regular with my cycle with my body being a clock. 4 years ago I was diagnosed as having PCOD and took tablets for the same and then 3 years back I had an issue with my endometrium becoming thick and took medication for that. Apart from that, the past two years everything was normal. I did proper exercise, had proper food and everything was normal. But the past one month I didn't have the time to exercise properly and I was under tremendous stress. My appetite gradually decreased and as a result of all this I'm having difficulty getting periods. I'm having spotting, white discharge and then nothing. Again spotting, white discharge and nothing. Severe body pain and crazy mood swings and bloating but no periods. What can be done?