Scanty Periods

Ladies I am getting pretty worried 
My periods have started to get shorter and shorter over the past year.. In my 20s they were consistent and lasted 6 days but I always have had long cycles of around 44/55 days. 
Now my cycle length is similar but my periods are dropping from consistent 6 days of flow to 5, 4, 3 now this is the first period I have that's scanty.. I have worn a pad for 2 days. Day one nothing hit my pad just when wiping I saw blood.. Mind you my first pad was from nigh time to morning, 2nd day it was so so light (streak of blood and no flow for whole day) I only see something when I wipe when in the bathroom... 
I'm scared that I'm moving into perimenopause or something - I'm 33 I have pcos and hypothyroid! 
I was planning on <a href="">IVF</a> ... And now this is happening. My consult is literally his week and am afraid they will tell me I have bad egg quality or going into menopause or something sinister like that...
Has anyone been in my position and can offer any advice ??