Fired From Job For Frequent Doctors Visits

Location: PA

This was a salaried, professional office based job.

For the past 3 months I have had a few minor and major health issues come up at once so I have had frequent visits with specialists, coming out to 10 visits over the past 12 weeks. I would put my appointment times on my work calendar as soon as they were scheduled and was usually able to schedule them to coincide with lunch, or late in the day so I could come in early and still get all of my work done. I would sometimes have to reschedule meetings but none of my work was impacted.

A week before I was let go I had to reschedule a meeting with my boss for earlier in the day because I had to schedule an appointment at 4 PM. My boss told me all of my appointments were "suspicious" and asked what they were for, which I didn't really feel comfortable divulging (mens health issues was what this appointment was for) so I just said health issues and he seemed pretty mad.

Last week I got called into his office and HR was there too and they said they were letting me go due to performance issues and consistently missing deadlines. I asked what deadlines I had missed (never had any negative comments about my performance at all and never missed a deadline) and it fell silent for a moment before my boss said "Don't play dumb with me, you were getting ready to quit anyway" and then he walked out of the room. I asked HR what was going on but they refused to answer any questions and just took my badge and escorted me to the door.

I've obviously put together that my boss thinks I was interviewing for other jobs. I'm wondering if any laws were broken here because I had actual medical issues? For reference my boss came in about 3 months ago from corporate to fill in for my old boss who retired suddenly, he and I did not have a particularly close relationship and everything we talked about was work related.