I would think that the relationship is more about hormones. The hormones that cause the nausea help sustain the pregnancy, which therefore allows the uterus to need to grow (which is usually the cause of cramping, but can also be the little critter burrowing into the uterus). Is that clear as mud!?!
With this pregnancy, I have had very little nausea compared to my previous pregnancies, but a lot of cramping. Though, these have been similar to Braxton Hicks, and not just the usual menstrual type cramps.
So, I have been concerned because of the extra cramping and lack of nausea, that the baby may have not developed. But, without spotting, I am hoping for the best.