Ovulation error?

My cycles tend to be short but the last two months they were actually 28 days.  I start testing around day 8 of my cycles, just in case I am going to have a shorter cycle again.
This month, I tested positive on day 9 (negative the next day - i know I don't need to test after receiving a positive but I do).  Very little spotting day 14 and this am which is day 15, for the heck of it, I took another ovulation test.  It's positive?  Spotting picking up now too.  
Using clear blue digital