Late period

I’m breastfeeding and my baby is 6 months. I got my period back 7 weeks PP. the cycle days have been increasingly longer and i know it can take up to a year for your cycle to be normal again. I don’t feel pregnant or anything, but i expected my period by now (last one was march 9-12) I honestly don’t know if/when I’ve ovulated. My husband and I use condoms here and there but not regularly and I’m not on bc because my body doesn’t react well-yes I’ve even tried an IUD and my body rejected it twice. He was also out of town until the 18th of March and i honestly don’t even know how many times we’ve had sex since starting my job because I’m exhausted most days I come home from it, so weekends are typical for us if we do. When should I test? I’m really not worried if i am and if i am, great, another baby! Although i know they recommend waiting at least 18 months, which is when we plan to try for the next one. I just don’t know when my period should be considered “late” pp.