If your skin problems worsen in a distinct pattern consistent with your menstrual cycle, it is very likely that PMS could be the cause of your spots and breakouts. Skin problems are a common symptom of PMS and they can appear up to seven days before your period.
To identify if PMS is causing your spots, I would advise you to try keeping a PMS Diary. In a diary or calendar note the days when spots appear. This will allow you to see if there is a pattern between when you get spots and when you start your period. After a few months of logging your spot prone days you should have your answer.