Getting pregnant after birth

So I just have a question. My so. Is almost 5 months old and I breastfed until he was about 3 months old. We are wanting to get pregnant again. We want our baby to have a sibling close in age. And we had to do <a href="https://glowing.com/glow-fertility-program">IUI</a> to get him. We struggled for about 2 years. I don’t want to struggle again. So I’m wondering how soon after completely stopping breastfeeding will you get your period. We haven’t used any protection since he was born. And I haven’t had a period yet. And how can you tell if you are ovulating without a period ?