I may be pregnant, my boyfriend ejaculated in me about two weeks ago and i took my birth control about 4 hours late the next day... could i be?

Take a test: It is hard to say never in anything medical, but your risk seems minimal. If you have been faithful in taking your pill daily a few hours delay one day should not make it ineffective. Missing a few days maybe but not a few hours. Failure rate with the pill runs 1-5% depending on several factors. Take a test or two if you miss your period.