am i pregnant? what should i do?

a couple days before my last period i had a little bit of a scare where the condom came off...we weren’t sure if any cum got in me but i took a plan b a couple days after it happened and then got my period a couple days after that and figured everything was okay. but now, about a month later, my period is 5 days late and i’m not sure if that’s just eve estimating incorrectly or if i should be worried...any advice?