I am flying from Detroit to Chicago, then London and finally Cairo (one itinerary.) I was wondering if it's possible to get my baggage checked all the way through to Cairo and not be charged for anything over the 20kg from bmi. I'm freaking out. This is the first time I've had such a strict rule for this type of flight, also they're overage charges are CRAZY. I've tried searching the old threads but most posts are a few years old and it seems like the policies have changed since then.

Thanks!