should I take a plan B pill?

Angela
I have been taking my pill regularly for a while and just ended my period less than 10 days ago and therefore am on the first week of my new pack of pills.
Last night, I had sex with my boyfriend and we didnt use a condom for foreplay. He says he didn't cum in me but I know you can get pregnant from pre cum. We used a condom for the rest of sex.
I missed my pill this morning and am getting on a plane soon which means my pills are in my checked bag and I won't have access to them until 9pm which is 11 hours later than when I usually take it.
Should I take a morning after pill when I can? (Which wouldn't be until tomorrow morning aka more than 24 hours after sex.) Or, is my risk of pregnancy low?
I'm pretty stressed out about this.