Alright, so here's our situation.
My brother was coughing a while back. He went into the doctor and they diagnosed him with pertussis, though he doesn't have insurance so they didn't do an actual test.
A few weeks ago, my husband developed a cough. This was before we had even heard about my brother's doctor visit and we thought it was allergies (which he was also suffering from pretty severely). My two daughters and I didn't show any symptoms, so we went on assuming it must be allergies. His cough continued, but of course he never made a "whooping" sound (most adults do not). He is still coughing about once an hour. A big hacking cough that he's super annoyed with, but he's fine. We decided that he must have whooping cough, but by the time we made this decision he was already beyond the really contagious stage, so there was no point in getting antibiotics. We assumed that the girls and I weren't getting it because of the fact that I'm fairly sure I had it 10 years ago (cough that lasted months, doctors never figured out why, but it was before they started to recognize that the vaccine wears off, so I'm guessing that's why they didn't think it was pertussis). From what I've read, the smallest of babies used to be protected from it by their mother's breast milk because of the antibodies she had from getting it in her childhood.
Yesterday, my 3 year old started coughing. She has had all of her DTaP shots (though I don't plan on giving her boosters now that I know better, but that's besides the point). She recently stopped nursing (a little over a week ago), so I don't know if that made her more susceptible. I also feel a bit of a tickle in my throat, which mades me doubt what I thought was immunity.
So, I don't know what to do about my 4 month old. She's not coughing at all, but since she's around my 3 year old and myself 24 hours a day, she's definitely exposed. She's nursing exclusively, so she's getting antibodies that way. I'm also going to go to the store today and get some vitamin C and elderberries for my daughter and myself to take and get our immune systems the best they can be.
I've cancelled my daughter's 4 month well check (she's actually 4.5 months, but the doctor was out of town for a bit) so that we won't expose all the kids at the doctor's office. I'm wondering if I should get the antibiotic for myself and my older daughter to lessen the risk of spreading it to my younger daughter, though I know the chances of her not getting it when everyone in the house has it are slim to none. I'm also afraid that the doctor will try to push giving her the DTaP vaccine (which I'm totally not okay with) or antibiotics (which I'm not happy about, but realize they have their place). What would you do?