Does anyone know why your feet would develop bumps in the night?

ha ha that sounds quite funny.
But… for the past 4 months now, I sometimes wake to weird lumps in my feet, around my arches, I can’t see them but can feel them. At first I thought they were mosquito bites but they weren’t really that itchy ( a little bit) and I could never see a bite per se.
They always go away once I“m up and walking on the foot.
Does anyone have any idea what they could be?
I would go to the Dr but they never last long enough – I only assume they are not mosquitos as I have my arms out most nights and never get bitten there when the lumps occur?
Any ideas?

I’m also carrying my darling LO around a lot these days – so could be weight placement maybe?