Ovulation for me was predicted anytime from the 16-20th of this month. I had sex on the 14th and my boyfriend came in me, I stood on my head for about a min and a half... what are the chances that I am pregnant?

About the same without the acrobatics.
Without knowing your medical history it's impossible to say, but you don't need to go to such extreme lengths.

As Curlyben said, unless you were to have fertility concerns, it is the same as anyone else's... about 20-25% if you were indeed close to ovulation. Odds are zero if you aren't. There is no need to stand on your head... it won't increase the odds.