I had to work for 3,5 hours in a small building that smelled of recent painting and still was a little dusty. could this have hurt my early pregnancy?

Paint fumes ?: Although it is unlikely that this kind of exposure would result in harm to your pregnancy, whenever there are solvents like paint, turpentine, gasoline, etc., the area should be well ventilated, and if not, you should not spend time in such an area. See your OB provider to make sure there are no effects on the fetal growth progression.