First of all, all the best wishes for the forthcoming new little family member!!! I remember when I gave birth to my first daughter, my mother was even more excited than me!!! Now my daughters are 11 and 7 years old, and my parents love them so much, they could die for them....
Now regarding colds, whenerver I catch a cold it usually begins with a runny nose, a sore throat and sometimes a low fever. Then after 2-3 days, my bowels start screaming!!!! So I know exactly how you feel. Try not to stress too much about a possible flare, because then you will definately have one!! I am going to be the maid of honor to my best friend's wedding this Saturday, and I have all these dark thoughts of needing to go to the bathroom etc. But I try to convince myself that everything will be just fine, and that I'll enjoy myself.
Keep smiling, and try to focus on your new grandaughter!!!
greek warm hugs,