Sorry if I missed this elsewhere but is the first tattoo you’ve gotten? Swimming is a big no, no during healing but I think you’ve thoroughly learned that lesson so I won’t dwell on that lol Also, staying out of the sun is another but I digress. If you have antibiotics then I’m assuming you’ve seen a physician as they’re not OTC unless you’re in another country I’m unaware of. You also may also contact the artist but I would bet they’ll say call your doctor so at this point all you can do is take your meds which depending on type may take some time to work. Keep an eye out for infection, follow the advice given, and seek emergency care if you run a really fever especially. If you choose to get another tattoo make sure you follow the advice. It’s there for a reason ya know? They want the work to turn out well and for their clients to be safe. If you truly believe you have some muscle or bone infection that’s another one for the doc but the tattoo in the pics doesn’t seem look red, ozzy, or anything but a try tattoo which is a normal part of healing. I know this is late but I hope things are much better a week or so out and you’re arm is feeling back to normal! Would love an update if you like sharing