does my toddler have chicken pox??????

my son is two years old and for the last few days or so hes been a bit unwell, having naps in the afternoon when he normally would not. a little bit of a temp. so iv been treating him with calpol and letting him nap when he wants. also had a bit of a runny nose. so my partner got him ready for bed last night who if im honest never notices unusualy things.... so when i got his clothes on this morning i noticed a bit of a rash. so firstly i noticed two spots, one on his back and one on his neck, they are like a little blister filled with fluid. then on his shoulder is what looks like exema, which is a cluster of red itchys flat spots. so i dont know what to think....... chicken pox was going around my daughters nursery but she does not have a rash or a temp.