Noone is going to tell you you are over reacting if you're worried about such a small baby, and they will be happy to check her out It does sound like more than just a cold. Even if its a virus and needs to run its course, it would be reassuring to know that and that she isn't deyhdrated I think I would try seldoc as you get an appt so there is no waiting about But if you're still worried after, Kings paeds a and e is very good It could be teething pain I would def try some calpol