Pregnant?

About 5 weeks ago , my boyfriend accidentally came in me because the condom broke and we didnt notice. I was in the middle of my period and I took a plan b 18 hours later. about a week , week and a half ago, i got this crazy head cold ( what I assume was a headcold ) and for a few days my head felt horrible and i absoloutely could not get confortable whether i was standing up or laying down and i felt super nauseous the whole time , but im a week late with my period ( accodding to this app ), what are the chances that im pregnant? im so nervous.