Condom Broke 🙄

Had sex with a guy I had been crushing on for four years. We agreed we would be fwb. First time we had sex together and in the second round the condom broke and neither of us noticed until he pulled out. Most got on the sheets but still. 
I got off my period the day before, and I know sperm can last a few days in a V. 
Question: when does your ovulation time frame start and end? I have a feeling this app is wrong about mine. So how can I tell? Just to be safe.