Yes, you can receive the COVID vaccine on April 18th even if you are currently taking an antibiotic for a urinary tract infection. It is always a good idea to inform the healthcare provider administering the vaccine about any medications you are taking. In rare cases, a fever could be a sign of a complication related to your infection rather than a side effect of the vaccine. However, the benefit of getting vaccinated outweighs the small potential risk of confusion. If you experience any side effects or complications after receiving the vaccine, be sure to mention that you were on antibiotics at the time of vaccination. If you have any doubts or further questions, it is always best to consult with a healthcare professional.