Kidney infection or ruptured cyst?

Has anybody ever had a kidney infection And remember where the pain was and what it felt like or even a cyst? I had a sharp pain on the front side of my stomach at 18 weeks and found out I had a UTI and cyst. The pain lasted a few hours and than went away. I am now going to be 21 weeks and the pain has shown up again and led in to my lower back, now my whole side of my body has the sharp pain. Not sure what to do? Help please 😩😩