Hi Rach
Swelling down there is quite common. It can happen at anytime after the first trimester. The tingeling sensation is caused by the swelling as is the widening.
Using your bowels more often than you normally do, can be caused by a number of things including anxiety/fear. And as you have had a bit of a scare this could be the cause. It could also be caused by a bug. There is a chance that when your cyst burst you could have picked up an infection. However as deesalie said it could also be a sign that labour is not too far away. I suggest that you take things easy for the next few days. If you start to get any contractions go to the hospital.