"I had my period 2/10/2011 and i had sex on 2/19/2011 and he ejaculated inside and now im experience stomach pains and headaches. Am i pregnant? And is it to early to take a test?"

Since today is the 23rd, it would be not only too early to test, but too early to be experiencing symptoms of pregnancy.

Bt could there be high chance?

There is always a chance when you have sex.