Because you've posted in the Erectile Dysfunction Community, I'll also answer this (despite your user name) as though you were male. When a male has an orgasm, the white stuff that comes out is semen, with sperm in it. A little fluid will also come out before the orgasm. I've never known a male not to be sure it was an orgasm when it was, so I do assume you're a gurl.
I assume you are female by your avatar, so the white stuff would be your vaginal secretions. If you are having an orgasm, you will probably know it. It feels like your vagina is sneezing.