I Just Had A Boy Four Months Ago And My

I just had a boy four months ago and my boyfriend and I had sex with a condom but later he end up taking it off. I have been on my pills but I haven't been taking them due to the fact I ran out of them and I have to get a doctors appointment for some more birth control pills. Is there a chance I can be pregnant even though he didn't ejaculate? What kind of cheap emergency contraceptives I can use?