You can use different names at different time. Obviously you can use the slang once when you'r being naughty, and the scientific names when you are being good.

I'm not quite sure either, but I've read somewhere that it should be during the time of your ovulation. I had once had a bad accident during the time of my ovulation. I missed my periods that month and I was worried. That's when I did a bit of a research and I found that if you are stressed or ill d...