Quick question

How do I know when im ovulating I have my calendar and it says my days are the 2nd through the 7th and the percentage is very high on the 6th and the 7th but how do I know when I am actually ovulating today I had some pain in the upper part of my vagina and lower part of my stomach but I have no milky discharge is just regular when I wipe myself (sorry for too much information) can I tell by simply looking at the toilet tissue when I am wiping myself or should I insert my fingers in my vagina in till that way