Mam, it sounds like mites, but I cannot see them. There are over a hundred different kinds. Often the offenders are the juvenile form and are noticable with the naked eye. It helps to have a positive i.d. to address the problem. I get a little nervous when I read the shotgun approach suggestions. I am also concerned that we are quick to treat our birds with the newest avaliable products without a good solid approach to dealing with the properly identified offender. Also if you suspect them in your house call a proffesional.
I am not saying that any advice that you have recieved is good or not. I just want to express a need for caution and thoughtfulness when dealing with these kind of problems. With you being pregnant please get your husband to handle any chemical. Also I hope that everyone is mindful of the fact that mites have a uniquely flexable DNA and are famous for becoming immune to particular chemicals. Also with their super reproductive life cycle it is worth considering that we could end up breeding a resistant strain on our property. If we treat for a particular offender we should do our best to erradicate them.
I also have not read anything about using heat to assist treating housing. I use a roofer's torch to treat the walls and floors of my houses. I then plastic off the openings and heat the houses. In the summer it is easy to get the temeratures up high enough to kill EVERYTHING in the house meaning mites, lice, bacteria, viruses etc. This can present it's own dangers if not done thoughtfully but is a non chemical method. The soil in the house is the most difficult to treat with chemicals or heat. For example chlorine becomes in active when applied to organic material. It is best to remove the top few inches before the house is treated. I use Sevin after heat treatment and a bleach clean out.
If we are going to deal with mites or similar we should make a good attempt to erradicate them from the birds, housing, and area around the housing (carefully). Then a product like ivermectin could be used as an aid.
I am not claiming that this is qualified advice to anyone, just an encouragement to be thoughtful, cautious, and thorough.