I'm sure ALPA legal could address this better but if my company were making me fear for my job if I didn't fly sick I would make dam sure I ASAP'd it. Something like, "I didn't feel that I was at my best to fly but felt that my job, the welfare of my family, was in jeopardy if I didn't."
It would have to be worded carefully but I'm sure there's a way that it could be worded.

I'd do that every time that I had a sniffle; the FAA sees everyone ASAP, fatigue report, etc that is filed and I bet they would not want it to get out that companies were coercing pilots to fly unfit.