I'm Sergei Tokmakov, California attorney (Bar #279869). FMLA retaliation isn't my home turf jurisdictionally but the federal framework is consistent across states.
The McDonnell Douglas burden-shifting framework applies: you establish a prima facie case (you requested protected leave, you suffered an adverse action, there's a causal connection — temporal proximity of 2 days clearly satisfies this), then the employer offers a non-retaliatory reason (the handbook violation), and you respond by showing that reason is pretextual (you have no prior writeups, the cited rule is vague, no specific conduct was identified).
For PA-specific representation find a local employment lawyer. Most take FMLA cases on contingency because of fee-shifting under 29 U.S.C. 2617(a)(3). EEOC isn't strictly necessary for FMLA claims (those go to DOL or directly to court) but if there's any disability or discrimination angle, file there too. 300-day window.
Document everything now while it's fresh. Informational only.