The chiyuv to hear every Parsha is a chiyuv of the Tzibur, not the Yachid – so technically, you’re OK if you miss a Parsha. That being said, if you’re in the US with a group of people, you can see if you can find a Minyan (and Ba’al Koreh) who are willing to Lein the whole Parshas Bechukosai at Shabbos Mincha before you fly back (i.e., call up Kohen, Levi, and then finish the Parsha on Yisrael) – that’s what happened once in a situation I was in where I and a group of relatives flew in to the US for a wedding. Good luck!
an Israeli Yid