My son has been very active too! I heard that they slow down a LOT once they start getting bigger and are running out of room in there. Probably because they feel more secure and comfy.
But at 31 weeks, you would think there isn't much room in there anyways! hahaha. Yeah I would love to have another ultrasound, mine was so short and I could hardly see anything but his spine. My technician was rushing so much that even though he moved, I couldn't see it because she moved to new positions too quickly. A shirt sounds like such a cute idea! I would love to see a picture! How did you make it? I've never been very good at personalizing clothes, but a shirt like that sounds so cute and I definitely want to try it.