HELP! Could i be pregnant ?

So me and my boyfriend had sex with a condom but it came off and he cummed in me. i wasn’t able to get the morning after pill straight away and i only had a 3% chance of getting pregnant that day. My period is due on Thursday and i really cannot have a child right now due to health and other reasons. Should i get the morning after pill or wait for my period to come?( It happened on saturday by the way -and i’m currently getting signs that my periods coming like normal)