silly question just curious though

Ruby
When do cravings start almost at my four week and yeah nausea goes back and forth as it has all dang day but I ate some pickles and suddenly my tummy doesn't want to throw up. 
I only ate the pickles because they looked good I wasn't exactly craving them. How ever because of a typhoon hitting Okinawa I don't get the vanilla milkshake I really wanted. 😂 My question to you all is when do the food cravings start?