Fishy smelling urine is usually a sign of an infection (sexually transmitted); but the condition most suspected is bacterial vaginosis
It is a simple infection which can be easily diagnosed and treated with effective antibiotic coverage.
In the meantime, I would advise you to abstain from sexual intercourse till at least 7 days after the last day of treatment.
Do not worry, all your symptoms are related to your infection and shall subside with adequate antibiotic treatment.
could be related to a hormonal
change occurring either due to a period or an infection that has resulted in menstrual irregularities.
I hope this helps.