Ds (3yo) went to bed Friday night with a very slightly swollen eye.
Saturday morning-completely swollen. No pain just wouldn't open.
Out of hours gp gave eyedrops for conjunctivitis whilst telling me "I'm not sure that it is conjunctivitis" 
Today (Sunday) ds wakes up crying. His eye is purple, swollen, closed over and he is saying his head is hurting and temp of 40. Call 111. Sent to out of hours who immediately sends us to a&e. All rushed through very fast and within 20 mins we are up on a ward he has numbing cream on his hand ready for iv antibiotics. Doctor goes off and speaks to consultant and between them decide they think it is periorbital cellulitis and not orbital and give oral antibiotics 3x a day for 10 days. We were under strict instructions return straight to the ward if we have any concerns that things are worsening or not improving fast enough just call ahead first.
We left hospital at 1pm and ds has slept since then. He won't eat (hasn't since tea yesterday) and just keeps crying saying his head is hurting. He's had 2 doses of antibiotics and his temperature has been 38.3 at lowest all day despite regular Calpol and Nurofen.
I am worried so I called the ward and she completely shot me down, saying that I've allowed no time for medicine to kick in yet. I'm also worried about the diagnosis being wrong as everything I've read (I know, I know) says that periorbital comes from a cut or a bite etc but ds had absolutely no signs of anything like that. He's had a cough and a snotty nose for a couple of days prior.
Would you go back tomorrow or should I allow longer for the meds to work? The eye DOES look less swollen tonight as in he is able to open a couple of mm, but it's the lethargy, temperature (currently 39) and the lack of appetite that are making me worry.