Worried

So my fiancé and I went through a little bit of a dry spell (like 2 weeks). We were both really stressed with his new job change and all the things that come along with it. So we finally talked about everything and trying to reduce the stress for each other and making the other feel appreciated which led to a lot more sexy time. The other night (Monday) we had sex and we use the withdrawal method, but this time there was no withdrawal we were too in the moment. So the next morning I went and got plan b. We both decided with a new job and planning a wedding it is not the time for a baby. But when I looked at my tracker it said I was ovulating. Now I know plan b is supposed to stop you from ovulating but what if you already are? Lately I have had such bad isomnia  and back pain and cramps I'm worried that plan b might not have worked. Can anybody help me?