When to test ? So confused irregular cycles

Kristen
So my periods have been irregular the last two cycles and changed to 34 days.
My LMP was December 28th. 
If I was back to a normal 28 I would be expected my AF on January 26th.
If I am a 34 day cycle it would be Feb 1st.
On January 26th I had sex then got really sharp pains in my left ovary. Went to the washroom and saw brown/pink werid looking blood figured my AF is starting and I changed back to a 28 day cycle. 
But although I had some cramping my AF hasn't actually started just light spottinf on and off for the past three days it's been from light pink to brown but nothing like a regular heavy flow. 
I don't need to wear a pad or anything but if I put a tampon in I can see light pink blood but it doesn't actually travel out of my body.
So I'm wondering if I should still test and if I do when should I test ? 
Did anyone have some trouble with cycle lengths and had light spotting and than get a bfp