OK bear with me 
I have never considered myself as having anything other than distinctly average nipples but apparently the fact they are getting squished flat whilst feeding is a sign that they are in fact too long 
DD was a small baby (6lb 1oz) and due to being a little early and very sleepy she dropped down to 5lb. My nipples became very sore and cracked with the constant feeding. I saw lots of MW's and BF advisors in the first ten days and was advised by all that latch wasn't a problem and that things would get better as she got bigger.
She is now 9 weeks and my nipples are still getting squashed flat. The main part of the feed is not painful but towards the end it gets uncomfortable and my nipples have developed hard white ridges, which are tender.
Is this going to get better? DD now weighs 9lb so I don't think her size is an issue and her weight gain has been better than expected but I would really like to look forward to a time where it is not painful.
She has also started to "fuss" quite a lot at the breast, pulling the nipple in her mouth and latching on and off constantly. I had thought she was suffering from wind (she looks uncomfortable) but now worry she may be struggling to get the milk she needs.