I don't know what it is but I don't think it would be contractions...I had similar sensations up around my ribs were it would tingle and feel numb. I asked my doc and she did not know what it was. I don't have it anymore...I think it was how the babies were laying!
When you are having contractions your belly will get really hard. If you poke it, it would be like poking your forehead. I don't ever remember it being up in my ribs though. I would say that if you are concerned, even if only slightly, you should call your Dr. It is always better to be safe rather than sorry. Good Luck!
I experience an uncomfortable feling right below my breasts and I have also experienced nubbing there. I think that it is just them laying sideways or the "growing pains" of skin stretching.
I am having terrible rib pain on my right side. I asked my doc why and he said it is because your liver, which is a very large organ, is on the right side of your body. That makes less room for the babies on your right side. So they are sort of stuck in that area which puts additional pressure on your rib cage. It hurts like crazy! Hurts when I sit down, and hurts terribly when I sleep. The only relief I get from it is when I stand up. And that is not exactly comfortable on other parts of my body. I guess there is no way for me to be comfortable any more.