vaginapagina | Thick white discharge??

Hey everyone! Quick question for ya'll...

I had sex last night and when we went to clean up, my boyfriend found thick white discharge on his penis. He said it smelled slightly like vinegar. I don't think it's a yeast infection for a few reasons. I'm not in any discomfort, its not itchy down there, and it didn't resemble that cottage cheese look or smell yeasty. It was just a smooth and thick and very white.

I did go get a pelvic exam friday and thought maybe the lubrication my doctor used could have something to do with it, but that was a few days ago. Another factor is that i was off my birth control for a month and just started again sunday. I haven't started my period yet and if everything goes correctly, i should be getting it in a week or so.

With this information, what do you guys think it could be??