What Are The Side Effects Of Using Levonorgestrel 1500 Mg?

i am 64kg 18yr old female.i had protected sex but at the end the condom slipped off halfway not fully! this occured today on the 6th day of my cycle which varies from 24to29 days. am i at a risk of getting pregnant? also i took the morning after pill last month having 1500mg of levonorgestrel.due to that i got my periods earlier this month.will this affect the length of my cycle permanently?