Last Night I Had Sex With My Boyfriend For The

Last night I had sex with my boyfriend for the first time without a condom, but I am on birth control. The thing is, I took my birth control pill at 12am the night before and didn't take another one until 2:40am the following day, also the pill I took at 2:40am after we had sex was the last one before I started my sugar pills. What is the likelihood of getting pregnant during this occurance. I had been taking my pills very regularity before this occurred.