I'm not sure. It could just be from holding it in, especially since there is so little room for your bladder and with you only being 14 weeks it'll only get worse. Just try to go to the bathroom more often maybe, and don't push, just let it come, even if its slow. I know when I go to the bathroom I have no control over how fast it comes out because the baby is taking up all the room. Its annoying but us pregnant women have to realize that the baby controls all our inner organs until they come out. XD
It could be a bladder infection. My only symptom when I have one is cramping, not everyone gets the "typical" symptoms.
I feel this often too, and I get checked for bladder infections/utis and I'm always negative. I think it's just the pressure of the baby :)