Breastfeeding and TTC

I have an 11 month old and I’m still Exclusively breastfeeding her. Me and my husband just decided it’s time to start trying for baby #2. I’m not on any pill and not really using any birth control. Also, haven’t had a period since November 2017. The last couple days I have been feeling period cramps and not quit right. We only just had unprotected sex like 5 days ago. Could I be pregnant that fast? Or could I be getting my period? I dunno but I know I’m feeling weird.