Need help

Me and my husband are trying to have a baby but I’m not sure when I ovulate. I got off my BC pills in December 2018 and been having irregular periods. Jan 15-19 a week later than normal then Feb I started 3 days later than normal on 16th very heavy then 17th it was light spotting then done. Has anyone else having this problem and if so how long did it take before you got pregnant off BC pills?