condomless sex, IUD, late period

i had sex without a condom May 27th at like 1:30am. my partner pulled out and now my period is late by almost two days. I got the Liletta IUD February 7th 2018. I’m pretty sure i got my period the day i got my IUD put in, and ever since that day my periods have been on schedule. until now.

is there a chance of pregnancy or is it the IUD effecting the cycle?