i need reassurance

so i came to canada (where im originally from) last friday night as my dad had taken a heart attack, it sounded very serious so i flew home. well as i was checking into the airport i scanned my passport and it said 'some countries want a passport valid for more than six months' mine was about seven months left before it was to expire. so fine i applied for an express passport when i came into halifax last week. thats not the issue, its all finished i just need to pick it up monday before i leave to go back to az. i am so worried because i have the worst luck. my luck i will get there and they will have said 'oh we sent it out ot you' when they said it would be available for pick up. then i always get so worried when going through customs on the way back to the US. i dont know why. i am always so scared they will not let me back into the US. anyways im sorry i just needed to vent, its been a very stressful week and a half. if im not stressed about one thing, im stressed about another. especially when it comes to crossing the border. now that my dad is going to be absolutly fine, i need something else to worry about i suppose!! if anyone can offer some reassurance about crossing back into the US so i dont get so anxious that would be wonderful......sorry to take up some space