I don't know what it is, but have you considered that you may have
contaminated your bedding. Urishinol can get on fabrics and persist
for some time. my mom had problems that way.

But it doesnt look like poison ivy (according to pictures I found on
google)

Also, I stay in a hotel during the week, and this weekend I took out
new blankets.
Same result, more bumps the next morning.

Thanks