It would be ideal to cut it out of your diet, but in limited amounts it should be okay. Just be mindful that coke has caffeine and the safe limit for caffeine during pregnancy is 200mg a day.
Try not to drink gassy or sugary drink much during pregnancy. Furthermore coke contains atleast 7 tblspoon of sugar.
Nah thats fine dear. You can also switch to sparkling water, h2o carbonated, 100 plus beside coke.