So this is a weird question and TMI

I am on cycle day 17. Yesterday after my work out (around 6-630) I came home and around 730 laid my son down to bed. Sometime between 630-7 I started feeling A LOT of pressure near where my uterus is and the pressure was also bearing down inside of my vagina and bum. 
I tried to go to the bathroom but I didn't really feel like I had to go besides the pressure. Plus it hurts if I even pushed a little bit.
What could this be? It's not as bad today but I can still feel it a little. Did I hurt something during my work out?