Just started zpack 4 sinus inf, think ear drum may have ruptured now. Should I see doc again? No leak, mild pain. What home care can I do?

Keep doing. Keep doing what you are doing. Typically an ear drum rupture will heal as long as you treat the infection that caused it. Acetaminophen or Ibuprofen should take care of the pain. There may yet be some drainage. As long as it continues to improve as expected, no change is needed. See your doctor if it gets worse or doesn't improve as expected.
Nothing. Ruptured eardrum, if happened, is common and typically heals very well and nothing need to be done. We used to puncture the drum to drain the pus and relieving the pain...Kids often have their eartubes for prevention of recurrent infections...After a year or so, they fall out and the drums heal back nicely. If no pain, no drainage, the not likely rupture.