Scab came off incision after shower this morning and left an opening, looks like it has pus in it. Should I be worried? (Photo)

Thanks for sharing your question and your pictures. Sorry to hear you are having some problems. This is likely due to inflammation and perhaps superficial infection around a suture. You should call the surgeon who performed your procedure and notify him or her. They may want to see you in the office and examine you. They may also want to treat you with local wound care, topical antibiotics, or systemic antibiotics depending on their preferences. Once these are open and draining, I tend to just have patients treat these with topical antibiotic ointment until they heal. Very rarely do they cause a significant problem and most of them heal up without you noticing anything in the long run.Good luck to you!

The yellow film often found under a scab is called fibrin which is part of healing tissue.  There is not surrounding redness so you don't have an infection.  With any incision concerns, you should always discuss them with your surgeon as they can see you in person.

I recommend consulting your PS for
specific instructions on this matter. In the meantime, keep the area clean and
covered. Best regards.