What Causes Missed Period, Dizziness, Chills, And Light Spotting While Having A History Of Irregular Periods Due To PCOS?

Hi doctor I m a 33 yr married women with 2children I have pcos but periods are irregular once or twice in a yr…but not exceeded more than 55 days …from past 4 months my periods are consistently on 40 and 42 days ..my Lmp was 22nd July…since then I didn’t get periods till now on 8th of sep I had dizziness in the afternoon I went to doctor..upt was done result was negative she gave b plex forte tablets and In the evening there was spotting …more like pink to brown discharge till 9th sep evening ….then period like cramps on lower left side of my plelvic area …for 3 days ..and from then I was feeling chills and my body temp remains to be between 97.8 to 98.2 …i ve tested for pregnancy for few times in these days all came to be negative ..I still feel dizzy without bplex..I feel less sleepy @night..what could b wrong doctor..