spotting or something else?

Has anyone ever had spotting for more than 16 days? Normally have af on 1st of every month and have been regular for years, been off birth control for about 3-4 years... since ttc my af has come week early for the last 2 months? 
It's only when I wipe and it's pink/light red colour. I take gabapentin daily for my fibromyalgia and iv started on depression tablets I was taking seven seas trying for a baby tablets but stopped them as thought it was that.. my af normally lasts for 5-7 days and is normally heavy flow but I don't even have to wear a pad...