Help me ladies!

Okay so here is a picture of my bbt chart... This is my second month bbt tracking also my first month using opks. We'll I recieved a positive opk on October the first and as you can see above it says I "ovulated" on the second day of October. I BD Sept 30, October 1 & October 2nd but NOT Oct 3rd. I read that you have an lh surge then 12-36 hours later you ovulate. Is this true? Did I BD at the right times?