Best time to take..visiting relatives with pets

I just recieved your dewormer in the mail. Now I am wondering when would be the best time to take it.. here is my situation: the whole family will be doing the parasite cleanse...we are taking a trip in exactly one month to visit relatives who have two dogs, we will be staying a week. If we start now with the dewormer we will finish the deworming the day we go on the trip. My question is should we wait until after we have been around the dogs to do the deworming or do the dewormer before we go on the trip? My thoughts are if we deworm then go on the trip we will be exposed to more parasites so soon after deworming. Should we plan to still be deworming while on the trip? What would you recommend?

thanks