Plan b and breastfeeding ?

No judgement please! Im almost 6 months post partum , I did a big whoopsies and had unprotected sex with my hubs .

I breastfeed part time and was wondering if plan b is safe while breastfeeding .

Also , I wonder if I haven’t had my period yet , if this will make my period show up all of a sudden?

Either way , any info is greatly appreciated