confused??

Charlotte
I had a positive opk with fertile cm on cd14 of a usual 28 day cycle.
Been having cramps and more fertile cm today on cd23-so just out of curiosity I tested again with an opk and got another strong positive.
I'm really confused. Af is due in 5 days so could I really be ovulating twice and this late in my cycle??
Having a lot of breast tenderness too which isn't normal for me at cd23. 
Any ideas what's happening?