Should I test?

So baby girl is 7 months and I got my period back around 5mpp. I was suppose to get my period on Sunday, had symptoms of cramping Saturday night and yesterday but I’ve yet to get my period. Fiancé and I were intimate on the 19th without protection, we’re not technically trying but also not fully preventing. Idk if I should take a pregnancy test or not? Last month my period was about a week later than the first month so idk if it’s cuz I’m back to exclusively breastfeeding that it’s becoming irregular again. Any advice or thoughts?