Baby intake unstable

Need some help on this please. My 2mo intake very unstable.. previously always 90-100ml, then suddenly her intake drop very badly turn out shes having some cold symptoms. After discharge her intake went higher around 80-100ml but mostly 80ml instead of 50-70ml. So i was wondering is it normal? Her block nose should be slightly better. She is back to active Poop wise still observing cause she only poop 3 times alot yest and today none. Please need some one who has experience in this and let me know the outcome. im stressing and worrying...