I Am On Birth Control. I Take It Regularly And

I am on birth control. I take it regularly and never miss a pill. I had unprotected sex on April 1st. My last period before that was March 23rd. My partner pulled out, however I am concerned if I should be worried about the possiblility of pregnancy. I don't want to go through the trouble of appointments and stress to my partner if it is unnecessary. I am 22 years of age and in decent shape if that makes any difference to the odds.