You may or may not freely admit to it but every girl has tried to sniff their underwear to guess the health of their body down there. If you are able to notice the distinct vaginal smells in your panties it really can tell you about your vaginal health. The smell of your vagina is not constant so it is important to know that change in smell is perfectly normal. It may remain constant for a long time but can also change as frequently as every hour. The main cause behind this is the pH level around your genital area.