The indication that you O'd is 3 days in a row of high temperatures. If you have 3 in a row of higher temps, then the O date is the
day before the big jump. The big jump verifies that you O'd. If you are using an online site, it should give you your O date after the 3 days of high temps.
Sorry I don't know anything about BV. The women on the Women's Health board on this site seem to talk about it a lot. They might be able to help you more.