When I was expecting my first child, everyone gave me all this advice about how I should breastfeed, the best bottles, nipple cream, diaper rash ointment, don't lay baby on tummy, etc....but then someone told me this: don't listen to all the advice other people so freely give you, it's your baby and you know what's best--go with your gut! (Pun intended!)
I know when my child is coming down with something and I know when it's just the sniffles. Nobody else can tell these things. It's a momma thing. And I've doubted myself a few times, but now that my second baby has come along, I'd say I'm pretty good at this whole momma thing. I trust my instinct! Of course I call my mom if the baby has a strange rash or is coughing and spitting up too much, we all need reassurance that we are not overreacting by calling the doctor. That's normal.
So, my advice is to trust your gut. Take others advice with a grain of salt. And do what you think is best for you and your baby. You know them best and you're the only momma they've got!