was too hot now I'm too cold?!

bug

So pre pregnancy I could be in a heatwave and cold, proper cold to the bone cold. Since getting pregnant I've felt no cold at all, quite warm to almost too hot. Today the hottest day so far (20°C, normally 16°C) I'm cold, like actually cold feet and cold all over and considering a bit water bottle. Eh what the......I don't understand why suddenly when everyone else is melting I'm cold? I'm 12 weeks and sitting in a heated house at 21°C with a fluffy blanket? Could it be due to the lack of temp difference so my body thinks it's cold - my partner says I'm normal to the touch?