Has anyone gotten pregnant while breastfeeding?

My son is 11 months old and we got pregnant with him on the first cycle after stopping the pill! We want our kids close in age so I stopped the mini pill about 2 months ago, but it took me 2-3 weeks to get my period on October 24.. but I've only had about 4 total since he was born. He still breastfeeds 4 times a day and 2-3 times at night. He only nurses for a short a time and he eats a lot of solids. I'm wondering how long it took others to get pregnant while breastfeeding and having irregular periods? I'm so anxious about it and I test obsessively since AF doesnt show up regularly. I don't even know how to calculate when I'm ovulating. Anyone else in the same boat or have a success story to share?