Hot Rod was neutered at 6 1/2 mos. He had never really lifted his leg but 1 time and it wasn't even really a lift-outdoors. He is 14 1/2 mos now and has started to lift his leg for about 1 month now. He is so cute, he will stand by the stop sign and lift the opposite leg.

The other day he lifted his leg on a giant leaf on the ground, ha, ha.
I have only seen him lift his left once in the house on his pad. It is in the family room where we always are so I can see him. I have read that you can put a water filled water bottle in the middle of the pad to give him something to aim for. So far he hasn't done it again.
He had 14 teeth removed at the same time and I was not given any pain meds. I should have gotten some. I think that he was in some pain and I felt awful for him. Fortunately he healed from the surgery well and we had no issues with the incision. Good luck with your little one.