OK all you wonderful, knowledgable ladies, I need your advice once again please

Olive has been eating well etc however on Friday when I took her for her 1yr old check up she hasn't put on any weight in 3mths. I wasn't particularly concerned about this as I think she is healthy and dh has a similiar build and very fast metabolism.
Then on sunday we went out and olive just couldn't get enough sleep which is unlike her and when she woke up wouldn't eat and then fell back to sleep on me for ages. When we got home I realised she had a temprature and she had it all night as well.
Well she hasn't had a temp since but is still refusing to eat and is also hardly drinking. We are worried but not sure if it's just a bad case of teething or some kind of sickness. She is being really fussy and clingy and after 4 days of eating harly more then a few bites of food per day I am quite concerned that she will lose weight and dehydrate. So should I take her to the doc's or am I wasting my time now that the temp has gone? Do you think it just sounds like teeth?

TIA