I am a little confused by your question, but understand you are worried that your pre-menstrual symptoms have changed suddenly.
You are no longer experiencing any of the negative symptoms that you usually do, including cramps, vomiting, nausea/not being able to eat, breast tenderness. You are now noticing spotting that is different. Is this all correct?
As the above post mentions, your cycle can change for no apparent reason, along with the symptoms. Problematic symptoms include excessive bleeding or pain. If you are not experiencing these symptoms, and are actually experiencing the opposite...that your PMS has gone away!..this is a good thing! Our cycles change as we get older, and visiting with your Gynecologist for an annual pap smear and medical evaluation will help ease your worries that something is wrong. Not experiencing symptoms....this is nothing to worry about!