G.♣.
You need to go to the doctor. Something is wrong with your stent. It sounds like the stone has become lodged again. Your ob and your urologist need to be working together on this one. Antibiotics and baby aspirin are not going to do anything for your kidney stone or the stent.
ETA - When you're pregnant, everything is related to the pregnancy. Your OB/GYN is your primary care physician and should be discussing your care with your urologist.