Does that so called fishy smell or scent only occur during ovulation?

Vaginal odor: May be a vaginal infection called BV that is common in women and not a sexually transmitted disease. Have the female checked for BV ( bacterial vaginosis), Flagyl can resolve it .Trichomoniasis can cause a fishy odor as well and is treated with Flagyl . Very very rarely fistulas or cancer can cause an odor. F/u with doctor

Only ovulation?: The acidity in vagina is changed according to hormonal changes ,thus fishy odor that subsequently corrects.