Concerns about ovulation

Hello all! I’m recently new to this app and was suggested by a friend. My husband and I recently decided to try for what will be, our first child. My whole life I’ve had very irregular periods. (Never the same time each month, lasting longer than normal, etc.) I’ve also had extremely heavy periods. When I went to the OBGYN about the issues, she assured me everything is fine. I go yearly like I should and am still insured everything is fine. I went on birth control years ago and it has since helped those issues. But now that I recently came off birth control, I’m concerned that these issues may resurface. If they do, I’m concerned I may not know when I’m actually ovulating. I know typical ovulation happens 14 days or so before your period, but if your period becomes irregular, is there any way of knowing when you are “most fertile?” This may sound like a stupid question, but I’m new to all this. Thank you all in advance!