Re: Forgetting proper latch?
Do you have a strong/overactive letdown? She could be bending your nipple back with her tongue, to slow the flow. But how you describe it sounds like she may have gone more shallow on the latch and she is compressing your nipple on her hard palate, rather than her soft palate. Do you notice a lipstick shape to your nipple when she unlatches? Is it a pinchy feeling while nursing? Really study the next time you nurse, it doesn't take much movement for her to get too shallow, you'll notice more of your areola is out of her mouth than normal, but it may not look like a huge difference from the outside. Just feel the roof of your own mouth, in a good latch the nipple would be just past the ridge of the hard palate, and you can feel how DD just taking in milimeters less of your areola/nipple, can easily cause pain.
I would think by now you'd know if she had a tongue or lip tie, which can also cause the type of pain you describe. Some posterior tongue ties can be tricky to see though. Stranger things have happened. We didn't notice DS2's obvious tongue tie until he was 6 weeks old and we were trying introduce a bottle and he couldn't latch on to it. Prior to that I had only had pinchy pain in my right nipple sometimes, and I just wrote it off to possible poor positioning at the breast.