Summarize:

For most women, vaginal discharge is perfectly normal and can range from being clear to milky white. Abnormal discharge will look greenish-yellow and frothy. A strong odour is also a sign of abnormal discharge.  Trichomoniasis is spread through contact with vaginal discharge which happens most often during vaginal intercourse. However, non-sexual transmission can sometimes occur from penetration from other items like douche nozzles. Fortunately, the parasite can only last up to 24 hours outside of the body. Trichomoniasis can cause redness, burning, and itching sensations at the genitals in some infected individuals. These symptoms may indicate a possible trichomoniasis infection or that of another STI.  Trichomoniasis causes irritation within the vaginal canal or vulva. Vaginal irritation can be normal if the irritation only lasts for a few days or gets better after treatment. However, if irritation persists or gets worse, it's best to talk to your doctor about it and get it properly diagnosed and treated. Trichomoniasis can cause inflammation and soreness in the genitals that can make intercourse uncomfortable. See a physician if you experience these symptoms, and do not participate in intercourse until you have been tested for STIs or STDs.  Avoid all forms of sexual intercourse including anal and oral sex until you've been tested and cleared. You should also inform your sexual partner or partners if you suspect you have an STI/STD and encourage them to also get tested and treated. Some clinics will help you inform your partners anonymously by giving them a contact slip that lets them know they have been exposed to a sexually transmitted infection. It won't have your name on it and it won't necessarily tell them what the infection is.
Monitor your vaginal discharge. Recognize abnormal genital symptoms. Do not ignore painful or unpleasant sexual intercourse or urination.