Am I Pregnant Question

Friday night my boyfriend and I were having sex the other night, and we were protected. He came with the condom on and then pulled out. When he did, we were both kind of in shock. It broke. He said most of it was still on the condom, but I told him he was totally wrong cuz I was able to tell. I've been freaking out. I just got over me period, the condom had spermicide on it, and I'm on birth control except for the fact that the medicine I'm on for my cold slightly lessens the effects of it. We went to the doctor to ask what he thought. When he heard that I'm birth control he said it's very unlikely that I'll we'll become pregnant. I asked the doc if I should take plan b, and he said I could if I want to but if I don't it wont really make a difference. I don't know what to do. The side effects of the plan b hit me real hard. Thats why I would like another opinion.