No longer on birth control

Today I got nexplanon taken out. I wanted to see if there is a few other women who may have gotten it taken out and their advice. I’m trying to avoid being pregnant. What is the best way to know when your ovulating, when your period is so irregular? Also are you very fertile as soon as the birth control comes out? Any tips to stay safe (obviously condoms) but should I avoid sex during my ovulation days? Hopeful with your answers I can feel a little better!

Thanks everyone!