Pregnancy with protection


How many mommas got pregnant using condoms alone? I know it’s possible but didn’t think it would be likely. I’m 3 days late.. but have been having cramps the last 2 days. And had a little discoloured discharge twice today, a little bit of brown blood but doesn’t seem to be my period. I don’t know if my period is just late or if I’m potentially pregnant. I have a test for the morning but looking for others experiences. I have been so tired lately but I have an 19 month old so Its hard to know if that’s why I’m tired lol. I appreciate any experiences you may want to share!