can u tell ure ovulating?

ive been on ocpills for a long time due to mild pcos.  i got off them  just now to ttc.  i usually have 35 to 45 day cycles.  so im on cd 12 and im cramping pretty bad like menstrual cramps (not that painful) , its way too early in my cycle n even for a 28 day cycle to ovulate i think....can u tell if ure ovulating?