Absolutely 2 sides to everything. The nurses at my clinic told me that I was to report any concerns straight away. I didn't have any but appreciated that they were adamant about it. It meant that I was never left feeling that I shouldn't bother anyone. Having the film on also meant that the area was checked once a week when it was reapplied.
And following on from @kezmusc ... I have also remained very cautious about sunlight on the area particularly since I love the sunshine. I invested in a couple of new rashies for the beach - 1 short-sleeved and 1 long-sleeved - giving me a choice for the strength of UV and time spent outside. I also stash light scarves in both cars (except when my husband decides to clean everything out of them!) just in case I get caught short somewhere - it gives me something to drape over that side to keep any sun off. You also don't want sunburn if you've had any lymph nodes taken as that can be a potential source of infection.